Herpetology/Crocodilians and Turtles
- 1 Order Crocodylia
- 2 Order Testudines/Chelonia
- 2.1 Family Chelydridae (snapping turtles)
- 2.2 Family Kinosternidae (musk and mud turtles)
- 2.3 Family Emydidae (box, pond, and marsh turtles)
- 2.3.1 Genus Terrapene (box turtles)
- 2.3.2 Genus Actinemys (western pond turtles)
- 2.3.3 Genus Malaclemys (diamondback terrapins)
- 2.3.4 Genus Graptemys (map turtles)
- 2.3.5 Genus Trachemys (sliders)
- 2.3.6 Genus Chrysemys (painted turtles)
- 2.3.7 Genus Pseudemys (cooters and redbellies)
- 2.3.8 Genus Clemmys (spotted turtle)
- 2.3.9 Genus Glyptemys (sculptured turtles - wood and bog turtles)
- 2.3.10 Genus Deirochelys (chicken turtle)
- 2.3.11 Genus Emydoidea (Blanding’s turtles)
- 2.4 Family Testudinidae (tortoises)
- 2.5 Family Cheloniidae (sea turtles)
- 2.6 Family Trionychidae (soft shelled turtles)
There are 3 families of Crocodylia, with 23 species total. These families are:
- Gavialidae, containing 2 species, encompassing gharials and false gharials;
- Crocodylidae, containing 14 species in 3 genera, encompassing crocodiles; and
- Alligatoridae, containing 7 species in 4 genera, encompassing alligators and caimans.
|Etymology||Latinizing of the Greek κροκόδειλος (crocodeilos), which means both lizard and Nile crocodile. Crocodylia, as coined by Wermuth, in regards to the genus Crocodylus appears to be derived from the ancient Greek κρόκη (kroke)—meaning shingle or pebble—and δρîλος or δρεîλος (dr(e)ilos) for "worm". The name may refer to the animal's habit of basking on the pebbled shores of the Nile.|
|Physical Appearance||Crocodilians range in size from the Paleosuchus and Osteolaemus species, which reach 1–1.5 m (3 ft 3 in–4 ft 11 in), to the saltwater crocodile, which reaches 7 m (23 ft) and weighs up to 2,000 kg (4,400 lb), though some prehistoric species such as the late Cretaceous Deinosuchus were even larger at up to about 11 m (36 ft) and 3,450 kg (7,610 lb). They tend to be sexually dimorphic, with males much larger than females. Though there is diversity in snout and tooth shape, all crocodilian species have essentially the same body morphology. They have solidly built, lizard-like bodies with elongated, flattened snouts and laterally compressed tails. Their limbs are reduced in size; the front feet have five digits with little or no webbing, and the hind feet have four webbed digits and a rudimentary fifth. The skeleton is somewhat typical of tetrapods, although the skull, pelvis and ribs are specialised; in particular, the cartilaginous processes of the ribs allow the thorax to collapse during diving and the structure of the pelvis can accommodate large masses of food, or more air in the lungs. Both sexes have a cloaca, a single chamber and outlet at the base of the tail into which the intestinal, urinary and genital tracts open. It houses the penis in males and the clitoris in females. The crocodilian penis is permanently erect and relies on cloacal muscles for eversion and elastic ligaments and a tendon for recoil. The testes or ovaries are located near the kidneys. The eyes, ears and nostrils of crocodilians are at the top of the head. This allows them to stalk their prey with most of their bodies underwater. Crocodilians possess a tapetum lucidum which enhances vision in low light. While eyesight is fairly good in air, it is significantly weakened underwater. The fovea in other vertebrates is usually circular, but in crocodiles it is a horizontal bar of tightly packed receptors across the middle of the retina. When the animal completely submerges, the nictitating membranes cover its eyes. In addition, glands on the nictitating membrane secrete a salty lubricant that keeps the eye clean. When a crocodilian leaves the water and dries off, this substance is visible as "tears". The ears are adapted for hearing both in air and underwater, and the eardrums are protected by flaps that can be opened or closed by muscles. Crocodilians have a wide hearing range, with sensitivity comparable to most birds and many mammals. They have only one olfactory chamber and the vomeronasal organ is absent in the adults indicating all olfactory perception is limited to the olfactory system. Behavioural and olfactometer experiments indicate that crocodiles detect both air-borne and water-soluble chemicals and use their olfactory system for hunting. When above water, crocodiles enhance their ability to detect volatile odorants by gular pumping, a rhythmic movement of the floor of the pharynx. The well-developed trigeminal nerve allows them to detect vibrations in the water (such as those made by potential prey). The tongue cannot move freely but is held in place by a folded membrane. While the brain of a crocodilian is fairly small, it is capable of greater learning than most reptiles. Though they lack the vocal folds of mammals and the syrinx of birds, crocodilians can produce vocalisations by vibrating three flaps in the larynx.|
|Ecology, Habitat and Diet||Habitat: Amphibious.
Predators: Tend to be at the top of the food chain.
Diet: Largely carnivorous.
|Behavior and Locomotion||Locomotion: Crocodilians are excellent swimmers. During aquatic locomotion, the muscular tail undulates from side to side to drive the animal through the water while the limbs are held close to the body to reduce drag. When the animal needs to stop, steer, or manoeuvre in a different direction, the limbs are splayed out. Crocodilians generally cruise slowly on the surface or underwater with gentle sinuous movements of the tail, but when pursued or when chasing prey they can move rapidly. Crocodilians are less well-adapted for moving on land, and are unusual among vertebrates in having two different means of terrestrial locomotion: the "high walk" and the "low walk". Their ankle joints flex in a different way from those of other reptiles, a feature they share with some early archosaurs. One of the upper row of ankle bones, the astragalus, moves with the tibia and fibula. The other, the calcaneum, is functionally part of the foot, and has a socket into which a peg from the astragalus fits. The result is that the legs can be held almost vertically beneath the body when on land, and the foot can swivel during locomotion with a twisting movement at the ankle. Crocodilians, like this American alligator, can "high walk" with the limbs held almost vertically, unlike other reptiles. The high walk of crocodilians, with the belly and most of the tail being held off the ground, is unique among living reptiles. It somewhat resembles the walk of a mammal, with the same sequence of limb movements: left fore, right hind, right fore, left hind. The low walk is similar to the high walk, but without the body being raised, and is quite different from the sprawling walk of salamanders and lizards. The animal can change from one walk to the other instantaneously, but the high walk is the usual means of locomotion on land. The animal may push its body up and use this form immediately, or may take one or two strides of low walk before raising the body higher. Unlike most other land vertebrates, when crocodilians increase their pace of travel they increase the speed at which the lower half of each limb (rather than the whole leg) swings forward; by this means, stride length increases while stride duration decreases. Though typically slow on land, crocodilians can produce brief bursts of speed, and some can run at 12 to 14 km/h (7.5 to 8.7 mph) for short distances. A fast entry into water from a muddy bank can be effected by plunging to the ground, twisting the body from side to side and splaying out the limbs. In some small species such as the freshwater crocodile, a running gait can progress to a bounding gallop. This involves the hind limbs launching the body forward and the fore limbs subsequently taking the weight. Next, the hind limbs swing forward as the spine flexes dorso-ventrally, and this sequence of movements is repeated. During terrestrial locomotion, a crocodilian can keep its back and tail straight, since the scales are attached to the vertebrae by muscles. Whether on land or in water, crocodilians can jump or leap by pressing their tails and hind limbs against the substrate and then launching themselves into the air.|
Family Crocodylidae (crocodiles)
Family Alligatoridae (alligators and caiman)
There are two extant species of alligator: Alligator mississippiensis (the American alligator) and A. sinensis (the Chinese/Yangtze alligator). There are six extant species of caiman: Caiman yacare (the Yacare caiman), C. crocodilus (the spectacled caiman), C. latirostris (the broad-snouted caiman), Melanosuchus niger (the black caiman), Paleosuchus palpebrosus (Cuvier’s dwarf caiman), and Paleosuchus trigonatus (the smooth-fronted caiman).
|Etymology||From the Spanish el lagarto (the lizard).|
|Physical Appearance||Aligators: Have a slow metabolism. Most of the muscle in jaw is evolved to bite and grip prey (muscles for closing are exceptionally powerful, and muscles for opening are very weak, able to be held shut using several rolls of duct tape for transportation). Gizzard stones often found in stomachs. Unidirectional movement of air through the lungs (like fish and birds) while most other amniotes have bidirectional/tidal breathing (air moves in one direction through the parabronchi, exits lung through inner branch, oxygen exchange takes place in extensive vasculature around the parabronchi). Have muscular, flat tails that propel them while swimming. Two kinds of white alligators are albino and leucistic: they are practically impossible to find in the wild and survive only in captivity (e.g. Aquarium of the Americas; New Orleans has leucistic alligators that were found in a Louisiana swamp in 1917). The Chinese alligator is fully armored (including the belly).
Differences from crocodiles: See #Family Crocodylidae (crocodiles)
Size: Average adult American alligator weight is 360 kg (790 lb) up to over 450 kg (990 lb). Average height is 4.0 m (13.1 ft) up to 4.4 m (14 ft). The largest ever American alligator was found in Louisiana and was 5.84 m (19.2 ft) long. Average adult male Chinese alligator rarely weighs over 45 kg (99 lb) or exceeds 2.1 m (6.9 ft).
Color: Black or dark olive-brown with white undersides (strongly contrasting white or yellow marks on juveniles which fade with age).
Caimans: Scaly skin. Average maximum 6-40 kg (13-88 lb) except for M. niger, which can grow to 1100 kg (2400 lb) and 5 m (16 ft). P. palpebrosus grows to 1.2-1.5 m (3.9-4.9 ft).
Differences between alligators and caimans: Caimans lack the bony septum between nostrils which alligators have, have ventral armor composed of overlapping bony scutes formed from two parts united by a suture, are relatively longer and more slender teeth, and have calcium rivets on scales that make hides stiffer and less valuable.
|Life Cycle||Adult life span not measured. An alligator at least 80 years old (named Muja) in Belgrade Zoo in Serbia brought from Germany in 1937 is the oldest alligator in captivity.
Eggs (summer): Female builds nest of vegetation (decomposition provides heat). Chinese alligators have the smallest eggs of any crocodilian. Sex of offspring fixed within 7-21 days of the start of the incubation (less than 30 degrees Celsius or 86 degrees Fahrenheit produces all females, and greater than 34 degrees Celsius or 93 degrees Fahrenheit produces all males). Nests constructed on leaves tend to be hotter (more males) than those constructed on wet marshes.
Young: Baby alligators use egg teeth to get out of egg. Hatchlings have a ratio of five females to one male. Females weigh significantly more. The mother defends the nest from predators and assists hatchlings to water, providing protection for about a year if they remain in the area. Adult alligators regularly cannibalize younger individuals: after the outlawing of alligator hunting, populations quickly rebounded because of the higher rate of survival of juveniles. Female caimans build large nests (can be over 1.5 m wide) and lay 10-50 eggs which hatch in around 6 weeks. Females take their young to a shallow pool of water where they can learn how to hunt and swim.
Mating season (late spring): Mature at length of 1.8 m (6 m). "Bellowing choruses" in April and May (large groups of animals bellow together for a few minutes a few times a day usually one to three hours after sunrise, accompanied by powerful blasts of infrasound). Males do a loud head-slap. Exhibit group courtship ("alligator dances")
|Ecology, Habitat and Diet||Effect on biodiversity: Increase plant diversity and provide habitats for other animals during drought by constructing alligator holes in wetlands. Feed on coypu and muskrats, which cause severe damage to wetlands through overgrazing. Keystone species in the Everglades.
Predators: Apex predator (may determine abundance of prey species like turtles and coypu). Caimans have few natural predators (humans are main predators). Jaguars and anacondas prey on smaller caiman species.
Habitat: Alligators intolerant to salinity, ponds, marshes, wetlands, rivers, lakes, swamps, brackish environments.
Diet: Eat foliage and fruit in addition to their usual diet of fish and meat. Young alligators eat small prey (e.g. fish, insects, snails, crustaceans, and worms) while mature alligators eat bigger prey (e.g. larger fish such as gar, turtles, mammals like coypu and muskrats, birds, deer, and other reptiles). Main diet is smaller animals that they can kill and eat in one bite. May kill larger prey by grabbing and dragging into the water to drown. Will consume carrion if hungry enough (larger ones known to ambush dogs, Florida panthers, and black bears). Consume bigger food through allowing it to rot or using a "death roll" (biting and then convulsing/spinning wildly until bite-sized chunks are torn off: tail flexing to a significant angle relative to body is crucial). Caimans hunt insects, birds, and small mammals and reptiles, in addition to a great deal of fish.
|Behavior and Locomotion||Less dangerous to humans than crocodiles (generally timid and tend to walk/swim away). Provoked into attack by people approaching alligators or alligator nests. Attacks are few but not unknown. Feeding alligators is illegal in Florida because eventually alligators will lose their fear of humans, which is a greater risk for both alligators and humans. Chinese alligator are the most docile of all crocodilians. Large males are solitary territorial. Smaller alligators are in larger numbers close to each other (have a high tolerance for alligators of similar size). Largest (both genders) defend prime territory. Caimans are fairly nocturnal.
Locomotion: Capable of short bursts of speed in very short lunges. Move on land through:
|Conservation Status and Efforts||American alligator: Least Concern
Chinese alligator: Critically Endangered (IUCN Red List) with only a few dozen believed to be left in the wild (far fewer than in zoos). Chinese alligators are preserved by the Rockefeller Wildlife Refuge and Miami MetroZoo and are a CITES Appendix I species (extreme restrictions on trade and exportation). In 1999, there were an estimated 150 Chinese alligators left in the wild. Most remaining wild individuals live in the Anhui Chinese Alligator Nature Reserve. In danger from habitat pollution and reduction (because of rice paddies and poaching for medicinal purposes). Some are exterminated (some farmers consider them a threat). In 1979, Anhui Research Center for Chinese Alligator Reproduction was founded and had a breeding success, turning 200 to 10,000. The Changxing Nature Reserve and Breeding Center for Chinese Alligators housed almost 4,000 alligators.
|Distribution||Distributions for species of alligator and caiman:
|Miscellaneous Information||Raised commercially for meat and skin (leather for luggage, handbags, shoes, belts, etc.). Helps with ecotourism. In 2010, the Archbishop of New Orleans ruled that alligator meat is considered fish for purposes of meat abstention.|
|Alternate names||Turtles/tortoises/terrapins (depends on variety of English being used as all of these words can be used to describe specific type of chelonians)|
|Etymology||The word chelonian is popular among veterinarians, scientists, and conservationists working with these animals as a catch-all name for any member of the superorder Chelonia, which includes all turtles living and extinct, as well as their immediate ancestors. Chelonia is based on the Greek word for turtles, χελώνη chelone, Testudines, on the other hand, is based on the Latin word for tortoise, testudo. Terrapin comes from an Algonquian word for turtle. Differences exist in usage of the common terms turtle, tortoise, and terrapin, depending on the variety of English being used; usage is inconsistent and contradictory. These terms are common names and do not reflect precise biological or taxonomic distinctions. The American Society of Ichthyologists and Herpetologists uses "turtle" to describe all species of the order Testudines, regardless of whether they are land-dwelling or sea-dwelling, and uses "tortoise" as a more specific term for slow-moving terrestrial species. General American usage agrees; turtle is often a general term (although some restrict it to aquatic turtles); tortoise is used only in reference to terrestrial turtles or, more narrowly, only those members of Testudinidae, the family of modern land tortoises; and terrapin may refer to turtles that are small and live in fresh and brackish water, in particular the diamondback terrapin (Malaclemys terrapin). In America, for example, the members of the genus Terrapene dwell on land, yet are referred to as box turtles rather than tortoises. British usage, by contrast, tends not to use "turtle" as a generic term for all members of the order, and also applies the term "tortoises" broadly to all land-dwelling members of the order Testudines, regardless of whether they are actually members of the family Testudinidae. In Britain, terrapin is used to refer to a larger group of semi-aquatic turtles than the restricted meaning in America. Australian usage is different from both American and British usage. Land tortoises are not native to Australia, yet traditionally freshwater turtles have been called "tortoises" in Australia. Some Australian experts disapprove of this usage—believing that the term tortoises is "better confined to purely terrestrial animals with very different habits and needs, none of which are found in this country"—and promote the use of the term "freshwater turtle" to describe Australia's primarily aquatic members of the order Testudines because it avoids misleading use of the word "tortoise" and also is a useful distinction from marine turtles.|
|Physical Appearance||The largest living chelonian is the leatherback sea turtle (Dermochelys coriacea), which reaches a shell length of 200 cm (6.6 ft) and can reach a weight of over 900 kg (2,000 lb). Freshwater turtles are generally smaller, but with the largest species, the Asian softshell turtle Pelochelys cantorii, a few individuals have been reported up to 200 cm (6.6 ft). This dwarfs even the better-known alligator snapping turtle, the largest chelonian in North America, which attains a shell length of up to 80 cm (2.6 ft) and weighs as much as 113.4 kg (250 lb). Giant tortoises of the genera Geochelone, Meiolania, and others were relatively widely distributed around the world into prehistoric times, and are known to have existed in North and South America, Australia, and Africa. They became extinct at the same time as the appearance of man, and it is assumed humans hunted them for food. The only surviving giant tortoises are on the Seychelles and Galápagos Islands and can grow to over 130 cm (51 in) in length, and weigh about 300 kg (660 lb). The largest ever chelonian was Archelon ischyros, a Late Cretaceous sea turtle known to have been up to 4.6 m (15 ft) long. The smallest turtle is the speckled padloper tortoise of South Africa. It measures no more than 8 cm (3.1 in) in length and weighs about 140 g (4.9 oz). Two other species of small turtles are the American mud turtles and musk turtles that live in an area that ranges from Canada to South America. The shell length of many species in this group is less than 13 cm (5.1 in) in length. The main internal organs of these reptiles are the lungs, heart, stomach, liver, intestines, and the urinary bladder. A cloaca serves both excretory and reproductive functions. Turtles have a complete skeletal system with partially webbed feet.
Neck retraction: Turtles are divided into two groups, according to how they retract their necks into their shells (something the ancestral Proganochelys could not do). The Cryptodira retract their necks backwards while contracting it under their spine, whereas the Pleurodira contract their necks to the side.
Head: Most turtles that spend most of their lives on land have their eyes looking down at objects in front of them. Some aquatic turtles, such as snapping turtles and soft-shelled turtles, have eyes closer to the top of the head. These species of turtle can hide from predators in shallow water, where they lie entirely submerged except for their eyes and nostrils. Near their eyes, sea turtles possess glands that produce salty tears that rid their body of excess salt taken in from the water they drink. Turtles have rigid beaks and use their jaws to cut and chew food. Instead of having teeth, which they appear to have lost about 150-200 million years ago, the upper and lower jaws of the turtle are covered by horny ridges. Carnivorous turtles usually have knife-sharp ridges for slicing through their prey. Herbivorous turtles have serrated-edged ridges that help them cut through tough plants. They use their tongues to swallow food, but unlike most reptiles, they cannot stick out their tongues to catch food.
Shell: Upper shell is carapace, lower shell is plastron, carapace and plastron are joined together by bridges, inner layer of shell made up of about 60 bones (that include portions of the backbone and the ribs, meaning the turtle cannot crawl out of its shell), outer layer of shell of most turtles is covered by horny scales called scutes that are part of its outer skin (epidermis) made of keratin, scutes overlap seams between shell bones and add strength to the shell, leatherback sea turtle and soft-shelled turtles have shells covered with leathery skin instead of horny scutes, rigid shell prevents turtles from breathing as other reptiles do (by changing the volume of their chest cavities via expansion and contraction of the ribs), adapted to lifestyle, commonly colored brown, black, or olive green (may have red, orange, yellow, or grey markings, often spots, lines, or irregular blotches in some species), land-based tortoises have much heavier shells than aquatic and soft-shelled turtles which need to avoid sinking in water and swim faster with more agility, lighter shells have large spaces called fontanelles between the shell bones, leatherback sea turtle shells are extremely light because they lack scutes and contain many fontanelles
pH buffer: Suggested by Jackson (2002) that the turtle shell can function as pH buffer, turtles use two general physiological mechanisms when they must endure through anoxic conditions (e.g. during winter periods trapped beneath ice or within anoxic mud at the bottom of ponds), turtle shell both releases carbonate buffers and uptakes lactic acid
Breathing: (1) Employ limb pumping, sucking air into their lungs and pushing it out by moving the limbs in and out relative to the shell and (2) when the abdominal muscles that cover the posterior opening of the shell contract, the pressure inside the shell and lungs decreases, drawing air into the lungs, allowing these muscles to function like the mammalian diaphragm; a second set of abdominal muscles face the opposite way and when they contract they expel air under positive pressure
Skin and molting: As mentioned above, the outer layer of the shell is part of the skin; each scute (or plate) on the shell corresponds to a single modified scale. The remainder of the skin has much smaller scales, similar to the skin of other reptiles. Turtles do not molt their skins all at once as snakes do, but continuously in small pieces. When turtles are kept in aquaria, small sheets of dead skin can be seen in the water (often appearing to be a thin piece of plastic) having been sloughed off when the animals deliberately rub themselves against a piece of wood or stone. Tortoises also shed skin, but dead skin is allowed to accumulate into thick knobs and plates that provide protection to parts of the body outside the shell. By counting the rings formed by the stack of smaller, older scutes on top of the larger, newer ones, it is possible to estimate the age of a turtle, if one knows how many scutes are produced in a year. This method is not very accurate, partly because growth rate is not constant, but also because some of the scutes eventually fall away from the shell.
Limbs: Terrestrial tortoises have short, sturdy feet. Tortoises are famous for moving slowly, in part because of their heavy, cumbersome shells, which restrict stride length. Amphibious turtles normally have limbs similar to those of tortoises, except that the feet are webbed and often have long claws. These turtles swim using all four feet in a way similar to the dog paddle, with the feet on the left and right side of the body alternately providing thrust. Large turtles tend to swim less than smaller ones, and the very big species, such as alligator snapping turtles, hardly swim at all, preferring to walk along the bottom of the river or lake. As well as webbed feet, turtles have very long claws, used to help them clamber onto riverbanks and floating logs upon which they bask. Male turtles tend to have particularly long claws, and these appear to be used to stimulate the female while mating. While most turtles have webbed feet, some, such as the pig-nosed turtle, have true flippers, with the digits being fused into paddles and the claws being relatively small. These species swim in the same way as sea turtles do (see below). Sea turtles are almost entirely aquatic and have flippers instead of feet. Sea turtles fly through the water, using the up-and-down motion of the front flippers to generate thrust; the back feet are not used for propulsion but may be used as rudders for steering. Compared with freshwater turtles, sea turtles have very limited mobility on land, and apart from the dash from the nest to the sea as hatchlings, male sea turtles normally never leave the sea. Females must come back onto land to lay eggs. They move very slowly and laboriously, dragging themselves forwards with their flippers.
|Life Cycle||Parents usually do not help young or care for eggs. Sex of young is usually temperature dependent.|
|Ecology, Habitat and Diet||Although many turtles spend large amounts of their lives underwater, all turtles and tortoises breathe air and must surface at regular intervals to refill their lungs.
Diet: A turtle's diet varies greatly depending on the environment in which it lives. Adult turtles typically eat aquatic plants; invertebrates such as insects, snails, and worms; and have been reported to occasionally eat dead marine animals. Several small freshwater species are carnivorous, eating small fish and a wide range of aquatic life. However, protein is essential to turtle growth and juvenile turtles are purely carnivorous. Sea turtles typically feed on jellyfish, sponge, and other soft-bodied organisms. Some species of sea turtle with stronger jaws have been observed to eat shellfish while some species, such as the green sea turtle, do not eat any meat at all and, instead, have a diet largely made up of algae.
|Behavior and Locomotion||Senses: Turtles are thought to have exceptional night vision due to the unusually large number of rod cells in their retinas. Turtles have color vision with a wealth of cone subtypes with sensitivities ranging from the near ultraviolet (UVA) to red. Some land turtles have very poor pursuit movement abilities, which are normally found only in predators that hunt quick-moving prey, but carnivorous turtles are able to move their heads quickly to snap.
Communication: While typically thought of as mute, turtles make various sounds when communicating. Tortoises may be vocal when courting and mating. Various species of both freshwater and sea turtles emit numerous types of calls, often short and low frequency, from the time they are in the egg to when they are adults. These vocalizations may serve to create group cohesion when migrating.
Intelligence: It has been reported that wood turtles are better than white rats at learning to navigate mazes. Case studies exist of turtles playing. They do, however, have a very low encephalization quotient (relative brain to body mass), and their hard shells enable them to live without fast reflexes or elaborate predator avoidance strategies. In the laboratory, turtles (Pseudemys nelsoni) can learn novel operant tasks and have demonstrated a long-term memory of at least 7.5 months.
|Conservation Status and Efforts||Nearly all species of sea turtle are endangered (poached and over-exploited for eggs, meat, skin, and shells; habitat destruction; accidental capture in fishing gear).|
|Miscellaneous Information||A group of turtles is known as a bale. The Eocene epoch (59-33.9 mya) was seemingly the golden age for turtle diversity.|
Family Chelydridae (snapping turtles)
Chelydridae belongs to the suborder Cryptodira and has two extant genera, Chelydra and Macrochelys. Chelydra has three species: C. serpentina (the common snapping turtle), C. acutirostris (the South American snapping turtle), and C. rossignonii (the Central American snapping turtle). Macrochelys has anywhere from one to three extant species, M. suwanniensis (the Suwannee snapping turtle, previously though to be part of M. teminckii), M. teminckii (the alligator snapping turtle), and M. apalachicolae (the Apalachicola snapping turtle, which is not generally recognized as a different species from M. teminckii).
|Etymology||C. rossignonii is in honor of the French-born coffee grower Jules Rossignon. M. temminckii is in honor of Dutch zoologist Coenraad Jacob Temminck.|
|Physical Appearance||Common snapping turtles: Powerful beak-like jaws. Highly mobile head and neck (origin of the specific name serpentina). Can bite handler even if picked up from the side of the shell or hind legs. Sharp claws (like dog claws except they cannot be trimmed). Claws are used for digging and gripping, not attacking—the legs are not strong enough for a swiping motion—or eating—no opposable thumbs. Rugged muscular build. Ridged carapace, usually 25-47 cm (9.8-18.5 inches) in adults. Usually weigh 4.5-16 kg (9.9-35.3 lb). The heaviest caught in the wild was 34 kg (75 lb). The heaviest native freshwater turtle in the north. Plastra are around 22.5 cm (8.9 inches) long, and almost all common snapping turtles that weigh over 10 kg (22 lb) are old males. They continue to grow throughout life and have snorkel-like nostrils positioned on the top of the snout. The have large heads relative to their bodies, broad and flat carapaces, cruciform plastra (giving them more efficient leg movement for walking along the bottom of ponds and streams), and the longest tails of any turtle.
Alligator snapping turtles: One of the heaviest freshwater turtles in the world. Large heavy heads and long, thick shells with three dorsal ridges of large scales (osteoderms) making them appear like an ankylosaurs. Solid grey/brown/black/olive-green and usually covered in algae. Radiating yellow patterns around eyes that break up outlines of eyes and keep turtles camouflaged. Star-shaped arrangement of fleshy, filamentous "eyelashes". In 1937, an alligator snapping turtle weighing 183 kg (403 lb) was found in Kansas (not verified). They continue to grow throughout life and are generally 8.4-80 kg (19-176 lb) and 35-80.8 cm (13.8-31.8 in). Males are typically larger, and specimens over 45 kg (99 lb) are generally very old males. Only the giant softshell turtles of Chitra, Rafetus, and Pelochelys reach a comparable size. The male’s cloaca extends beyond the carapace edge while the female’s is at the carapace edge or nearer to the plastron. The male’s tail is thicker at the base because of the reproductive organs. The inside of the mouth camouflaged with a vermiform (worm-shaped) appendage on the tip of the tongue used to lure fish (Peckhamian mimicry). Alligator snapping turtles have a bite force about the same level as humans relative to size (158 plus or minus 18 kgf, 1550 plus or minus 180 Newtons, or 348 plus or minus 40 lbf). They can still bite through handle of a broom but rarely can bite human fingers clean off. They have four marginal scutes (unlike C. serpentina).
|Life Cycle||High and variable mortality of embryos and hatchlings. Delayed sexual maturity. Extended adult longevity. Iteroparity (repeated reproductive events). Low reproductive success per reproductive event.
Common snapping turtles: Females mature later at a larger size (15-20 years) in northern populations compared to southern populations (12 years). Maximum age of over 100 years. Eggs are vulnerable to crows, minks, skunks, foxes, and raccoons. They are laid in sandy soil some distance from the water. Females lay 25-80 eggs each year, guiding the eggs into the nest using the hind feet and covering the nest with sand for incubation and protection. Incubation period is temperature dependent (8 to 18 weeks). Eggs overwinter in the nest in cooler climates. Hatchlings are vulnerable to the aforementioned predators as well as herons (mostly great blue herons), bitterns, hawks, owls, fishers, bullfrogs, large fish, and snakes. Mate from April to November (peak June and July). Females can hold sperm for several seasons.
Alligator snapping turtles: Believed to be able to live to 1200 (although 80-120 is more likely). Typically live between 20 and 70 years in captivity. Mature at around 12 years, with a size of around 8 kg (18 lb) and 33 cm (13 in). Mate yearly (early spring in the south and later spring in the north).
|Ecology, Habitat and Diet||Habitat: Freshwater – common snapping turtles prefer shallow ponds and streams (some in brackish environments such as estuaries) and are extremely cold tolerant, remaining active under ice during winter and capable to diving to over 2-3 meters.. They come on land only to lay eggs.
Predators: Large, old, male common snapping turtles are at the top of their food chain. C. serpentina adults are sometimes ambushed by northern river otters during hibernation. Reported predators are coyotes, black bears, alligators and larger cousins, and alligator snapping turtles.
Diet: The common snapping turtle consume both animal and plant matter and is an important aquatic scavenger. Common snapping turtles are also active hunters that prey on anything they can swallow (e.g. invertebrates, fish, frogs, other reptiles like snakes and smaller turtles, unwary birds, and small mammals), which can be detrimental to breeding waterfowl since they will occasionally take ducklings and goslings. They are a somewhat flatulent species due to their varied diet. The alligator snapping turtle is also opportunistic and almost entirely carnivorous, relying on catching food and scavenging. Alligator snapping turtles will eat anything they can catch and target abundant and easily caught prey, e.g. fish, fish carcasses, molluscs, carrion, and amphibians. They are also known to eat snakes, crayfish, worms, water birds, aquatic plants, and other turtles and on occasion prey on aquatic rodents like nutria and muskrats or even small mammals like squirrels, opossums, raccoons, and armadillos.
|Behavior and Locomotion||C. serpentina is combative when out of water. It will make a hissing sound and release a musky odor when stressed. It is likely to hide itself under sediment when in water. Common snapping turtles sometimes bask by floating on surface with only the carapace exposed. They also bask on fallen logs in early spring in the north and may lie beneath a muddy bottom with only the head exposed in shallow waters (stretching their long necks to the surface for an occasional breath). If an unfamiliar species is encountered (such as humans), they may become curious and survey the situation (rarely may bump their nose on a person’s leg) if an unfamiliar species is encountered. Travel extensively over land to reach new habitats (can be driven to move by pollution, habitat destruction, food scarcity, overcrowding, etc.) or to lay eggs. Hibernating snapping turtles do not breathe for (in the northern region) more than six months. They can get oxygen by pushing their head out of the mud and allowing gas exchange between mouth membranes and throat membranes (extrapulmonary respiration). They utilize anaerobic pathways if there is not enough oxygen to burn sugars and fat. However, there is an undesirable side-effect from this process that comes in spring known as oxygen debt.
M. temminckii hunts diurnally by keeping its mouth open and imitating the motions of a worm using its tongue (the mouth is then closed with tremendous force and speed). Younger turtles catch minnows this way while larger turtles must catch more food more actively. There are no reported human deaths by alligator snapping turtles, and they are not prone to biting. They most often hunts at night, and adults have been known to kill and eat small American alligators.
Locomotion: Moving sideways is significant slower. They are capable of swimming up, swimming down, and walking.
|Conservation Status and Efforts||Least concern: however, their life history is sensitive to disruption by human activity (target for surveys, ID of major habitats, investigation and mitigation of threats, education of public including landowners, etc. from governmental departments, universities, museums, and citizen science projects). M. temminckii is a threatened species (CITES III limits exportation from the US and international trade) and is protected by state law in Kentucky, Indiana, Illinois, and Missouri, as well as labeled “in need of conservation” in Kansas.|
|Distribution||Distribution by species:
|Miscellaneous Information||It is a misconception that snapping turtles can be picked up safely by the tail (doing so will harm the turtle’s tail and vertebral column). Trying to rescue a snapping turtle by getting it to bite a stick and then dragging it out of danger will severely scrape the legs and underside of the turtle (leading to deadly infections). The safest way to pick up a snapping turtle is using a shovel or gasping the carapace above the back legs or picking up the corners of a blanket or tarp with the turtle in the middle. They are raised on some turtle farms in China. Common snapping turtles may be invasive in Italy and Japan from unwise exotic pet releases. Snapping turtles are a traditional ingredient in turtle soup (however, this may be toxic due to bioaccumulation). They are sometimes captive bred as an exotic pet; however, they do not make good pets – hand feeding is dangerous, and extreme temperatures result in the turtle refusing to eat. It is illegal to keep M. temminckii as a pet in California (where alligator snapping turtles do not naturally occur). Alligator snapping turtles were released into Czech Republic and Germany. Four were caught in Bohemia, and they are considered an invasive species in Oregon (where one was captured and euthanized in October 2013 in the Prineville Reservoir).|
Family Kinosternidae (musk and mud turtles)
Kinosternidae belongs to the suborder Cryptodira and is split into two subfamilies, Kinosternon (consisting of subfamilies Kinosternoninae – with Kinosternon spp., the mud turtles, and Sternotherus spp., the musk turtles – and Staurotypinae – with Claudius angustatus, the narrow-bridged musk turtle and Staurotypus spp., the Mexican/giant/three-keeled/cross-breasted musk turtles). Staurotypinae may be better as a separate family (Staurotypidae). There are 24+ species.
Musk and mud turtles are also called kinosternids (alluding to the familial name). They are close relatives to Chelydridae, the snapping turtles.
|Alternate names||Musk turtles are also known as stinkpots.|
|Etymology||Musk turtles are capable of releasing a foul-smelling musk from their Rathke’s glands, most similar to those of snapping turtles, under the rear of shells when disturbed. Some species also release foul-smelling secretions from the cloaca.|
|Physical Appearance||Size: Most are small, reaching 10-15 cm or 3.9-5.9 in SCL. Sternotherus spp. can be the smallest turtles, growing to 8-14 cm (3.1-5.5 in) while Staurotypus spp. can grow to 30 cm (12 in) and have large heads. C. angustatus turtles generally grow to 16.5 cm (6.5 in). Old individuals have especially large heads.
Distinguishing features: Have highly domed carapaces with distinct keels down the center.
Sexual dimorphism: Females are significantly larger while males have much longer tails.
Color: Various, ranging between black, brown, green, and yellowish. Some have a distinctive yellow striping along the sides of the head and neck. Most have no shell markings. Some species have radiating black markings on each carapace scute.
Shell: Hindlimbs are mostly invisible when the turtle is at rest. The plastron is hinged in some species (allowing them to wholly enclose their limbs, neck, and tail inside their shells). The carapace is usually solid, lacking the hinges and mobile/flexible zones present in some turtles. Have oblong and moderately domed carapaces. Plastron ranges from reduced to covering the whole shell, with fewer than 10 epidermal marginal scutes. Musk turtles have small and cruciform plastra that give them more efficient leg movement for walking along the bottom of ponds and streams. Staurotypus spp. turtles have plastra of only seven or eight scutes.
Genus differences: Mud turtles are generally smaller than musk turtles and do not have as highly domed carapaces. Three-keeled musk turtles have yellow undersides with brown, black, or green bodies and have three distinctive keels that run their length (hence the name). Narrow-bridged musk turtles are typically brown with wood-like scutes (in terms of lines and graining) and often have bright-yellow markings (algae often heavily covers these color markings as they age). They have extremely narrow bridges, such that they can rotate their plastra independently of their carapaces and such broad and narrow heads that they cannot be retracted into the shell. Barbels present on the chins and throats of some Sternotherus species. S. depressus turtles (flattened musk turtles) have relatively wide and flat shells, which may be an adaptation for hiding in crevices along the banks in which they live. Mud turtles lack endoplastra.
|Life Cycle||Breed in late spring and early summer. Lay around four hard-shelled eggs (sometimes 1 or 2 huge eggs, sometimes 10 or more tiny eggs). Some species overwinter in subterranean nests (emerging the following spring). Some adults spend winter on land (constructing burrows with small air holes used on warm days). Ranges from female-dominated to male-dominated sexual size dimorphism. Some produce a single clutch in the spring while some nest multiple times in the summer and some nest nearly year-round. Sex determination ranges from genetic with sex chromosomes to temperature-dependent. Embryonic development is direct in some species whereas other species exhibit early embryonic diapause and/or late embryonic estivation. Incubation periods range from 56 to over 366 days.|
|Ecology, Habitat and Diet||Habitat: Freshwater aquatic systems (slow moving bodies of water, often with soft, muddy bottoms and abundant vegetation). Some species inhabit highly seasonal ephemeral ponds which may only contain water for a few months of each year. Range from north temperate to tropical and rainforest to grasslands to desert. Brumate on land. Can forage on land. Occupy underground retreats/communal nests. Occasionally nest below vegetation.
Predators: Racoons eat the eggs of Kinosternon subrubrum (the Eastern/common mud turtle) while herons and alligators often hunt the adults.
Diet: Carnivores. Feed mainly on mollusks (snails and clams), crustaceans, insects, annelids, small fish (usually as fresh carrion), and even small carrion. Some are highly specialized mollusk feeders and eat little else. Some also eat algae and the seeds and leaves of certain plants. Grab and crush hard-shelled prey.
|Behavior and Locomotion||The yellow mud turtle (Kinosternon flaviscens) is the only species of turtle suspected to exhibit parental care (studies in Nebraska suggest that the females sometimes stay with the nest and may urinate on the eggs long after laying them, either to keep them moist or to protect them from snake predation by making them less palatable). Sternotherus spp. are highly aquatic. However, the common musk turtle is known to bask on fallen trees and coarse woody debris on shorelines. Musk turtles are almost entirely aquatic, spending much of their time walking along the bottom, foraging for food. They are often nocturnal. C. angustatus is a ferocious biter. Some kinosternids can undergo submerged and fully aquatic respiration. Some can estivate underground for up to two years.
Locomotion: Capable of limited climbing and will sometimes ascend steep slopes or sloping branches or logs, sometimes falling onto boats from overhanging branches or fallen trees.
|Conservation Status and Efforts||Most Kinosternidae species are common, reaching amazing population densities (as high as 1,200 per 2.5 acres [1 ha]). However, two tropical, one subtropical, and one temperate species are listed as Vulnerable on the IUCN Red List. The two tropical species (K. dunni and K. angustipons) are lowland forms with very restricted ranges and hence are probably affected most negatively by habitat destruction. The subtropical species (K. sonoriense) lives primarily in permanent water systems in the deserts of the U.S. Southwest; human competition for water resources has eliminated most of the habitat for this species. K. subrubrum is exploited by the pet trade and listed as an endangered species in Indiana. The temperate species (Sternotherus depressus) also has a restricted distribution in the permanent streams of north-central Alabama; habitat destruction associated with coal mining and forest clear-cutting seems to have caused the declines in this species.|
|Distribution||Musk turtle: North and South America (Sternotherus spp. in southern Canada, US, and Mexico; Staurotypus spp. in Mexico and Central America, Claudius spp. in Mexico, Guatemala, and Belize)
Mud turtle: US, Mexico, Central America, South America (great species richness in Mexico, only three species in South America)
|Miscellaneous Information||Sternotherus odoratus (the common musk turtle/stinkpot) is the most common species of Sternotherus in North America. Kinosternids do not have a good fossil record.|
Family Emydidae (box, pond, and marsh turtles)
Genus Terrapene (box turtles)
Terrapene belongs to subfamily Emydinae and is comprised of 12 taxa and 4 species (T. carolina, the common box turtle, T. coahuila, the Coahuilan/aquatic box turtle, T. nelsoni, the spotted box turtle, and T. ornata, the western/ornate box turtle). Terrapene was coined by Merrem in 1820 as a genus separate from Emys for those species that had a sternum separated into two or three divisions and that could move these parts independently. The Asian box turtle belongs to a separate genus, Cuora.
|Etymology||Terrapene is derived from the Algonquin for turtle. English writers in 1834 referred to them as box-tortoises from their resemblance to tightly closed boxes when the head, tail, and legs are drawn in.|
|Physical Appearance||Has a domed shell which is hinged at the bottom (allowing it to close its shell tightly to escape predators).|
|Life Cycle||Chance of death seems not to increase with age after maturity is reached. Average lifespan of 50 years. Significant portion live over 100 years. Growth directly affected by amount of food, type of food, water, illness, et cetera. Age cannot be estimated by counting growth rings on scutes. Eggs are flexible and oblong (on average 2-4 cm or 1-2 in and 5-11 g or 0.2-0.4 oz). Normal clutch size of 1-7 eggs. Average clutch size is larger in more northern populations while southern and captive box turtles have more than one clutch per year. Risk of death is greatest in small individuals due to size and weaker carapace and plastron. Many hatchlings die during their first winter. Adult shells are seldom fractured but still vulnerable to surprise attacks and persistent gnawing/pecking.|
|Ecology, Habitat and Diet||Habitat: Wide variety (varies on a day-to-day, season-to-season, and species-to-species basis). Generally mesic woodlands (moderate/well-balanced supply of moisture). T. ornata is the only species regularly found in grasslands. The desert box turtle T. o. luteola is found in semideserts (rainfall predominantly in summer). The Coahuilan box turtle T. coahuila is found in a 360 square-km region characterized by marshes, permanent presence of water, and several types of cacti.
Predators: Commonly mammals such as minks, skunks, raccoons, dogs, and rodents. Also can be killed by birds (e.g. crows and ravens) and snakes (e.g. racers and cottonmouths).
Diet: Omnivores with a varied diet. Basically eat anything they can catch. Mostly invertebrates (e.g. insects, earthworms, and millipedes) as they are plentiful and easy to catch but also 30-90% vegetation. Also eat fruits (e.g. cacti, apples, and several species of berry) and gastropods (e.g. Heliosoma and Succinea). Speculated that for the first 5-6 years they are primarily carnivorous and adults are primarily herbivorous, but there is no scientific basis for such a difference. Box turtles have been reported eating birds and small rodents that were trapped or had already died. Some species will eat poisonous mushrooms on a regular basis, making them poisonous to predators.
|Behavior and Locomotion||Defend from predators by hiding, closing the shell, and biting. Tend to move farther into woods prior to hibernation, where they dig a chamber for overwintering. Ornate box turtles dig chambers of up to 50 cm. Eastern box turtles become dormant at a depth of about 10 cm. Location of overwintering can be up to 0.5 km from the summer habitat and is often in close proximity to the previous year's. Active year-round in more southern locations as observed in T. coahuila and T. carolina major. Other box turtles in hotter locations are more active (T. carolina yukatana) or only active during the wet seasons.|
|Conservation Status and Efforts||T. coahuila is endemic to Coahuila and classified as endangered (range reduced by 40% in past 40-50 years; population reduced from well over 10000 to 2500 in 2002). T. carolina is the most widely distributed and classified as vulnerable. T. ornata is near threatened. T. nelsoni has insufficient information.
Efforts and concerns: Sniffer dogs have been trained to find and track box turtles as part of conservation efforts. It is recommended to buy captive bred box turtles (in the regions where this is allowed) to reduce pressure put on wild populations. A 3-year study in Texas found that over 7000 box turtles were taken from the wild for commercial trade and a similar study in Louisiana found that in a 41-month period, nearly 30000 box turtles were taken from the wild for resale, many for export to Europe. Turtles once captured are often kept in poor conditions where up to half of them die. Those living long enough to be sold may suffer from conditions such as malnutrition, dehydration, and infection. Indiana, Tennessee, and other states prohibit collecting wild turtles. Many states require a permit to keep them. Breeding is prohibited in some states for fear of its possible detrimental effects upon wild populations. Box turtles have a low reproduction rate, intensifying the negative impact of collecting box turtles from the wild.
|Distribution||The Coahuila box turtle is found only in the Cuatro Ciénegas Basin in Coahuila, Mexico.|
|Miscellaneous Information||Box turtles do not make good pets for small children. They are easily stressed by over-handling, require more care than generally thought, get stressed when moved into new surroundings, may wander aimlessly until they die trying to find their original home, and can carry Salmonella. The three-toed box turtles (T. carolina triunguis) are often considered the best box turtles to keep as pets since they are hardy and seem to suffer less when moved into a new environment. Box turtles require an outdoor enclosure and consistent exposure to the sun and a varied diet; otherwise, growth can be stunted and the immune system can be injured. Box turtles appeared abruptly in the fossil record (essentially in modern form), which may indicate that they are a generalist species (able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources) as opposed to a specialist species. It is complicated to establish how evolution from other turtles took place. The oldest fossils were found in Nebraska (15 mya in the Miocene) and resemble the aquatic box turtle. T. ornata and T. carolina fossils date from 5 mya. The only recognized extinct subspecies, T. carolina putnami, dates from the Pliocene (5.33-2.58 mya) and had a carapace length of 30 cm (12 in) which is much larger than other species. Box turtles are the official state reptiles of four states (North Carolina and Tennessee honor T. carolina carolina, the eastern box turtle while Missouri honors T. carolina triunguis, the three-toed box turtle, and Kansas honors T. ornata, the ornate box turtle). Pennsylvania almost named the eastern box turtle as the state reptile (passed through one house of legislature).|
Genus Actinemys (western pond turtles)
Actinemys belongs to the subfamily Emydinae and has one species, A. marmorata. The taxonomy of the western pond turtle is currently under debate; at present, the IUCN Red List recognises that the western pond turtle belongs in its own genus. However, there is deliberation that it may belong to the genus Emys which is composed of the European pond turtle (E. orbicularis), the Sicilian pond turtle (E. trinacris), and Blanding’s turtle (E. blandingii) which may belong in a separate genus itself (Emydoidea). There were previously thought to be two subspecies of the western pond turtle: the southern western pond turtle (A. m. pallida) and the northern western pond turtle (A. m. marmorata), but now there is evidence for four separate groups, which do not match the distribution of the earlier described subspecies.
|Alternate names||Pacific pond turtle, Emys marmorata, Clemmys marmorata|
|Etymology||The specific name marmorata refers to the marbled pattern of both the soft parts and carapace.|
|Physical Appearance||Color: The carapace is usually light to dark brown or dull olive, either with no pattern or with an attractive pattern of fine, dark radiating lines on the scutes. The plastron is yellowish, sometimes with dark blotches in the centers of the scutes. The limbs and head are olive, yellow, orange, or brown, often with darker flecks or spots.
Size: The shell is 11-21 cm (4.5-8.5 in) in length. The carapace is low and broad, usually widest behind the middle. Adult carapaces are smooth, lacking a keel or serrations.
Sexual dimorphism: In males, the cloaca is positioned beyond the edge of the plastron, whereas in females, it does not reach the edge of the plastron. Males have a yellow or whitish chin and throat, a flatter carapace, a more concave plastron, and a more pointed snout than females.
|Life Cycle||Thought to live for up to 40 years. May survive more than 50 years in the wild.
Hatchlings: Hatchlings from northern California northward overwinter in the nest, which may explain the difficulty researches have had in trying to locate hatchlings in the fall months. Winter rains may be necessary to loosen the hardpan soil where some nests are deposited. It may be that the nest is the safest place for hatchlings to shelter while they await the return of warm weather. Whether it is hatchlings or eggs that overwinter, young first appear in the spring following the year of egg deposition. Western pond turtles develop slowly in areas with short or cool summers, taking up to eight years to reach sexual maturity (may even be 10-12 years). They can grow relatively fast in warmer regions and in some nutrient-rich habitats, where they can reach maturity in half that time.
Breeding: Occurs in late spring to mid-summer, with mating taking place under water. Most mature females nest every year, some laying two clutches per season. In early summer the eggs are deposited in the nest, which is generally dug in soil, close to a water source, but some females may dig their nests many meters away from the water's edge (some may move as much as 800 m or half a mile away and up to 90 m or 300 ft above the nearest source of water, but most are within 90 m or 300 ft of water). The female usually leaves the water in the evening and may wander far before selecting a nest site, often in an open area of sand or hardpan that is facing southwards. The nest is flask-shaped with an opening of about 5 cm (2 in). Females spend considerable time covering up the nest with soil and adjacent low vegetation, making it difficult to find unless disturbed. The female lays an average of 4-7 eggs (range 1-13) per clutch, which hatch after ~13-17 weeks.
|Ecology, Habitat and Diet||Habitat: Occur in both permanent and intermittent waters, including marshes, streams, rivers, ponds, and lakes. Favor habitats with large numbers of emergent logs or boulders, where they aggregate to bask. Also bask on top of aquatic vegetation or position. Often overlooked in the wild. Terrestrial habitats are also extremely important since many intermittent ponds can dry up during summer and fall months along the west coast, especially during times of drought. Can spend upwards of 200 days out of water. Have been found more than 1 km away from water. Many overwinter outside of the water, often creating their nest for the year.
Predators: Generally well protected due to hard shell. Several predators threaten A. marmorata, especially hatchlings due to their small size and soft shell. Raccoons, otters, ospreys, and coyotes and the biggest natural threats, and hatchlings have the additional threats of weasels, bullfrogs, and large fish.
Diet: Omnivorous. Most of their animal diet includes insects (aquatic insects and larvae), crayfish, and other aquatic invertebrates. Small fish, tadpoles, and frogs are eaten occasionally, and carrion is eaten when available. Plant foods include filamentous algae, lily pads, tule, and cattail roots.
|Behavior and Locomotion||Possible to observe resident turtles by moving slowly and hiding behind shrubs and trees. Can be encouraged to use artificial basking substrate (rafts) which allows for easy detection of the species in complex habitats. Bask on mats of floating vegetation, floating logs, or on mud banks just above the water's surface. Engage in aquatic basking in warmer climates by moving into the warm thermal environment in or on top of submerged mats of vegetation.|
|Conservation Status and Efforts||Extirpated in Canada (May 2002: Canadian Species at Risk Act). Vulnerable on the IUCN Red List due to habitat destruction (ponds, wetlands, contamination of other water sources), conversion of wetlands to farmlands, water diversions, and urbanization. Listed as endangered in Washington State and protected in Oregon and California. Pet trade has declined over recent years for this turtle. Occasional losses from illegal collection for food by immigrant populations from Asia. Mortality from motor vehicle collisions. Predation from introduced species (e.g. bullfrogs).
Efforts: Commercial harvest or take of western pond turtles has been prohibited in all U.S. states where it is found since the 1980s. The recent increase in stock ponds and other man-made water sources appears to have a positive impact on population numbers and a few "head-start" programs (where the young are raised in captivity until their shells begin to harden and they are less susceptible to predation) claim to have had excellent survivorship rates after being released into the wild. However, re-introduction is limited if the habitat of the species is not protected.
|Distribution||Originally ranged from northern Baja California, Mexico north to the Puget Sound region of Washington. As of 2007, they have become rare or absent in the Puget Sound area. They have a disjunct distribution in most of the Northwest, and some isolated populations exist in southern Washington. Pond Turtles are now rare in the Willamette Valley north of Eugene, Oregon, but abundance increases south of that city where temperatures are higher. They may be locally common in some streams, rivers and ponds in southern Oregon. A few records are reported east of the Cascade Mountains, but these may have been based on introduced individuals. They range up to 305 m (1,001 ft) in Washington, and to about 915 m (3,002 ft) in Oregon (sea level to 1500 m). They also occur in Uvas Canyon area, Santa Cruz Mts, California, and in the North Bay, and lakes such as Fountaingrove Lake.|
Genus Malaclemys (diamondback terrapins)
Malaclemys belongs to the subfamily Deirochelyinae and has one species, M. terrapin, which has seven subspecies. The Bermuda population has not been assigned a subspecies.
|Etymology||Terrapin from the Algonquin word for turtle (torope). Diamond pattern on carapace.|
|Physical Appearance||Shell: Overall pattern and coloration vary greatly. Usually wider at the back than in the front (appears wedge-shaped from above).
Color: Shell can vary from brown to grey (greyish to nearly blackish carapace). Body can be grey, brown, yellow, or white. All have a unique pattern of wiggly, black markings or spots on their body and head. One of the darkest species of turtle.
Size: Greatest sexually dimorphic size disparity found in any North American turtle. Males grow to approximately 13 cm (5.1 in) while females grow to an average of around 19 cm (7.5 in). Largest female on record was just over 23 cm (9.1 in). Specimens from regions that are consistently warmer in temperature tend to be larger than those from cooler areas in the north. Males weigh 300 g (11 oz) on average while females weigh around 500 g (18 oz). Largest females can weigh up to 1000 g (35 oz).
Distinguishing features: Tuberculate (knobbed keel). Higher shell with a deeper bridge. Deeper gular notch. Consistently white upper lip. Uniformly colored carapace and plastron. Skull with a long and bony temporal arch.
Adaptations to environment: Can survive in varying salinities. Skin is largely impermeable to salt. Have lachrymal salt glands not present in their relatives which are used primarily when the turtle is dehydrated. Can distinguish between drinking water of different salinities. Exhibit unusual and sophisticated behaviors to obtain fresh water, such as drinking the freshwater surface layer that can accumulate on top of saltwater during rainfall and raising their heads into the air with mouths open to catch falling rain drops. Strong swimmers. Large and strongly webbed hind feet but not flippers as sea turtles have. Strong jaws for crushing shells of prey (e.g. clams and snails) like their relatives Graptemys. Females have larger and more muscular jaws than males.
|Life Cycle||Eggs: Clutches of 4-22 (usually not more than 4-8). Clutch sizes vary latitudinally with average clutch sizes as low as 5.8 eggs/clutch in southern Florida to 10.9 in New York. Are 1-inch long, pinkish-white, oval-shaped, and covered with leathery shells. Hatch in late summer or early fall. Usually hatch in 60-85 days, depending on the temperature and the depth of the nest. Favor females (almost six to one).
Hatchlings: Usually emerge from the nest in August and September but may overwinter in the nest after hatching. Sometimes stay on land in the nesting areas in both fall and spring and may remain terrestrial for much or all of the winter in some places. Freeze tolerant, which may facilitate overwintering on land. Hatchlings have lower salt tolerance than adults (one- and two-year-old terrapins use different habitats than old individuals use). 1-1.5 in long. May spend their first years upstream in creeks. Move back down to nutrient-rish salt marshes as they grow older where there are plenty of nesting sites.
Growth: Growth rates, age of maturity, and maximum age are not well known for terrapins in the wild. Males reach sexual maturity before females due to their smaller adult size. Sexual maturity is dependent on size rather than age (in females at least). Estimations of age based on counts of growth rings on the shell are as of yet untested so it is unclear how to determine the ages of wild terrapins. Maturity in males is reached in 2-3 years at around 4.5 inches (110 mm) in length while maturity in females is reached in 6-7 years (8-10 years for northern populations) at around 6.75 inches (171 mm).
Mating: Occurs in early spring. Able to produce eggs for several years after a single mating. Courtship has been seen in May and June and is similar to that of the closely related red-eared slider (Trachemys scripta). Females can mate with multiple males and store sperm for years, resulting in some clutches of eggs with more than one father. Temperature dependent sex determination. Females can lay up to three clutches of eggs per year in the wild and up to five clutches per year in captivity. Unknown how often they may skip reproduction so true clutch frequency is unknown. Females may wander considerable distances on land before nesting. Nests are usually laid in sand dunes or scrub vegetation near the ocean in June and July, but nesting may start as early as late April in Florida. Females dig a nest cavity 4-8 inches deep and will quickly abandon a nest attempt if they are disturbed while nesting. Quickly return to the ocean after covering the nest and do not return except to nest again.
|Ecology, Habitat and Diet||Habitat: Brackish coastal tidal marshes. Spartina (cordgrass) marshes that are flooded at high tide. Also Floridian mangrove swamps. Favor reedy marshes. Can survive in freshwater as well as full-strength ocean water but adults prefer intermediate salinities. Unclear why terrapins do inhabit the upper reaches of rivers within their range, as they tolerate freshwater in captivity. They are possibly limited by distribution of their prey. Live close to shore unlike sea turtles and require freshwater for drinking purposes.
Predators: Nests, hatchlings, and sometimes adults are eaten by raccoons, foxes, rats, and many species of birds, especially crows and gulls.
Diet: No competition from other turtles, though snapping turtles do occasionally make use of salt marshes. May eat enough organisms at high densities to have ecosystem-level effects, specially since periwinkle snails have a tendency to overgraze important marsh plants. Diet is not well studied. Data comes from southeastern end of range. Eat shrimp, clams, crabs, mussels, and other marine invertebrates (especially periwinkle snails). Also eat fish, insects, and carrion. Will only eat soft-shelled mollusks and crustaceans because they use the ridges in their jaws to crush prey.
|Behavior and Locomotion||Tend to live in the same areas for most or all of their lives. Do not make long distance migrations. Many aspects are poorly known because nesting is the only activity that occurs on land. Limited data suggest that terrapins become dormant in the colder months in most of their range in the mud of creeks and marshes. Quick to flee and difficult to observe in the wild. May be possible to observe them basking on or walking between oyster beds and mudflats. Mild-mannered. Excellent swimmers and will head for water if approached. Known to recognize habits in captivity and learn quickly what times people are normally around. Seem very sociable except when their cage is too small. Enjoy basking together (often one on top of the other).|
|Conservation Status and Efforts||In the 1900s the species was once considered a delicacy to eat and was hunted almost to extinction. The numbers also decreased due to the development of coastal areas and, more recently, wounds from the propellers on motorboats. Another common cause of death is the trapping of the turtles under crabbing and lobster nets. Due to this, it is listed as an endangered species in Rhode Island, is considered a threatened species in Massachusetts and is considered a "species of concern" in Georgia, Delaware, Alabama, Louisiana, North Carolina, and Virginia. The diamondback terrapin is listed as a “high priority species” under the South Carolina Wildlife Action Plan. In New Jersey, it was recommended to be listed as a species of Special Concern in 2001. In July 2016, the species was removed from the New Jersey game list and is now listed as non-game with no hunting season. In Connecticut there is no open hunting season for this animal. However, it holds no federal conservation status. The species is classified as Near Threatened by the IUCN due to decreasing population numbers in much of its range.
Threats: The major threats to diamondback terrapins are all associated with humans and probably differ in different parts of their range. People tend to build their cities on ocean coasts near the mouths of large rivers and in doing so they have destroyed many of the huge marshes terrapins inhabited. Nationwide, probably >75% of the salt marshes where terrapins lived have been destroyed or altered. Currently, ocean level rise threatens the remainder. Traps used to catch crabs both commercially and privately have commonly caught and drowned many diamondback terrapins, which can result in male-biased populations and local population declines and even extinctions. When these traps are lost or abandoned (“ghost traps”), they can kill terrapins for many years. Density of predators are often increased because of their association with humans. Predation rates can be extremely high; predation by raccoons on terrapin nests at Jamaica Bay Wildlife Refuge in New York varied from 92-100% each year from 1998–2008. Terrapins are killed by cars when nesting females cross roads, and mortality can be high enough to seriously impact populations. Terrapins are still harvested for food in some states. Terrapins may be affected (suffocated?) by pollutants such as metals and organic compounds, but this has not been demonstrated in wild populations. Hatchlings can get trapped in tire tracks left by vehicles on the beach, get dehydrated, and die before reaching water. There is an active casual and professional pet trade in terrapins and it is unknown how many are removed from the wild for this purpose. Some people breed the species in captivity and some color variants are considered especially desirable. In Europe, Malaclemys are widely kept as pets, as are many closely related species.
Efforts: The Diamondback Terrapin Working Group deals with regional protection issues. There is no national protection except through the Lacey Act, and little international protection. Diamondback terrapins are the only U.S. turtles that inhabit the brackish waters of estuaries, tidal creeks and salt marshes. With a historic range stretching from Massachusetts to Texas, terrapin populations have been severely depleted by land development and other human impacts along the Atlantic coast. Terrapin-excluding devices are available to retrofit crab traps; these reduce the number of terrapins captured while having little or no impact on crab capture rates. In some states (NJ, DE, MD), these devices are required by law. Relationship with humans: In Maryland, diamondback terrapins were so plentiful in the 18th century that slaves protested the excessive use of this food source as their main protein. Late in the 19th century, demand for turtle soup claimed a harvest of 89,150 pounds from Chesapeake Bay in one year. In 1899, terrapin was offered on the dinner menu of Delmonico's Restaurant in New York City as the third most expensive item on the extensive menu. A patron could request either Maryland or Baltimore terrapin at a price of $2.50. Although demand was high, over capture was so high by 1920, the harvest of terrapins reached only 823 pounds for the year. According to the FAA National Wildlife Strike Database, a total of 18 strikes between diamondback terrapins and civil aircraft were reported in the US from 1990 to 2007, none of which caused damage to the aircraft. On July 8, 2009, flights at John F. Kennedy Airport in New York City were delayed for up to one and a half hours as 78 diamondback terrapins had invaded one of the runways. The turtles, which according to airport authorities were believed to have entered the runway in order to nest, were removed and released back into the wild. A similar incident happened on June 29, 2011, when over 150 turtles crossed runway four, closing the runway and disrupting air traffic. Those terrapins were also relocated safely. The Port Authority of New York and New Jersey installed a turtle barrier along runway 4L at JFK to reduce the number of terrapins on the runway and encourage them to nest elsewhere. Nevertheless, on June 26, 2014, 86 terrapins made it onto the same runway, as a high tide carried them over the barrier. Their population is controlled by the raccoon population; it has been shown that as the raccoons decrease in number, mating terrapins increase, leading to increased turtle activity at the airport. Diamondback terrapins were heavily harvested for food in colonial America and probably before that by Native Americans. Terrapins were so abundant and easily obtained that slaves and even the Continental Army ate large numbers of them. By 1917, terrapins had become a fashionable delicacy and sold for as much as $5 each. Huge numbers of terrapins were harvested from marshes and marketed in cities. By the early 1900s populations in the northern part of the range were severely depleted and the southern part was greatly reduced as well. As early as 1902 the U.S. Bureau of Fisheries (which later became the U.S. Fish and Wildlife Service) recognized that terrapin populations were declining and started building large research facilities, centered at the Beaufort, North Carolina Fisheries Laboratory, to investigate methods for captive breeding terrapins for food. People tried (unsuccessfully) to establish them in many other locations, including San Francisco.
|Distribution||The very narrow strip of coastal habitats on the Atlantic and Gulf coasts of the United States, from as far north as Cape Cod, Massachusetts to the southern tip of Florida and around the Gulf Coast to Texas. A population of terrapins on Bermuda has been determined to be self-established (not introduced by humans).|
|Miscellaneous Information||Maryland named the diamondback terrapin its official state reptile in 1994. The University of Maryland, College Park has used the species as its nickname (the Maryland Terrapins) and mascot (Testudo) since 1933, and the school newspaper has been named The Diamondback since 1921. The athletic teams are often referred to as "Terps" for short. The terrapin has also been a symbol of the Grateful Dead because of their song "Terrapin Station". Many images of the terrapin dancing with a tambourine appear on posters, T-shirts and other places in Grateful Dead memorabilia.|
Genus Graptemys (map turtles)
Graptemys belongs to the subfamily Deirochelyinae and comprises 13 species and 15 taxa.
|Alternate names||Sawback turtles|
|Etymology||Sawback because the keel can result in vertebral spines in some southern species. Map-like markings on carapace.|
|Physical Appearance||Has a keel that runs the length of the carapace through the center. Intricate head markings. Strong sexual dimorphism (mature females are twice the length and 10 times the mass as mature males). Females can be split into three groups (while males do not fit neatly with differences in head width not influencing diet).
Microcephalic females: Narrow headed. Sympatric (occur in same place) with a broader headed species. Consume few mollusks. Include yellow-blotched map turtles (G. flavimaculata), black-knobbed map turtles (G. nigrinoda), ringed map turtles (G. oculifera), Quachita/Sabine map turtles (G. ouachitensis ouachitensis and G. o. sabinensis).
Mesocephalic females: Moderately broad heads. Tend to eat mostly mollusks along with soft bodied prey. Include Cagle's map turtles (G. caglei), northern/common map turtles (G. geographica), false/Mississippi map turtles (G. pseudogeographica pseudogeographica and G. p. kohni), and Texas map turtles (G. versa).
Megacephalic females: Exceptionally broad heads. Feed almost exclusively on mollusks. Include Barbour's map turtles (G. barbouri), Escambia map turtles (G. ernsti), Pascagoula map turtles (G. gibbonsi), Pearl River map turtles (G. pearlensis), and Alabama map turtles (G. pulchra).
Common map turtles: Females are 18-27 cm (7-10.5 in), and males are 9-17 cm (3.5-6.5 in). Light markings that resemble waterways on a map or chart. Lines on the carapace are a shade of yellow or orange and are surrounded by dark borders. Rest of carapace is olive or grayish brown. Markings on older turtles may be barely visible because of darker pigment. Carapace is broad with moderately low keel. Hind of carapace is slightly scalloped shaped due to scutes. Plastron is plain yellowish. Head, neck, and limbs are dark olive, brown, or black with thin yellow, green, or orangish stripes. Oval spot located behind the eye off most specimens. Sexual dimorphism in size and shape. Males have a more oval carapace with a more distinct keel, a narrow head, longer front claws, and a longer and thicker tail. Males also have a cloaca that opens beyond the edge of the carapace whereas the female's opens up at the carapace.
|Life Cycle||Average life expectancy ranges from 15-100 years. 5.5 years in captivity.
Eggs: G. geographica has a clutch size between 6-20 with ~3.2 cm (1.3 in) oval eggs that have a flexible shell and that hatch between 50-70 days of incubation. Common map turtle eggs have temperature-dependent sex determination (25 degrees Celsius will give a majority of males whereas 30-35 degrees will yield more females).
Hatchlings: Young have pronounced dorsal keels. Patterns on the plastron consist of dark lines bordering the scutes (light circular markings). Hatchlings have rounded grey or greyish-brown carapace, about 3 cm (1 in) long. Stripes located on the head and limbs are just like the adults'. Most G. geographica turtles emerge in August or September; they overwinter in nests if they hatch late.
Mating: Have greatly elongated claws on the front feet which are used in courtship behavior. The male faces the female and "fans" her face, vibrating his foreclaws against her head to induce her to cooperate in mating. G. geographica turtles mate in the spring and fall, mostly taking place in deep waters. The nesting period for common map turtles lasts from May to July, and they prefer unshaded sites with sandy soil. Female common map turtles usually mature at around 14 years old, and they usually choose well-drained areas for depositing eggs, digging the nest cavity with their hind feet and filling the cavity after the eggs are laid; they usually lay two or more clutches in one breeding season.
|Ecology, Habitat and Diet||Habitat: G. geographica turtles prefer ponds, river bottoms, and lakes, with an abundance of aquatic vegetation and areas with fallen trees and other debris for basking; they prefer large bodies of water.
Diet: G. geographica turtles are omnivores, and feeding always takes place in the water. Adult female common map turtles (due to their large heads and strong jaws) eat larger prey than the males, e.g. snails, clams, and crayfish. Male common map turtles eat aquatic insects, snails and smaller crustaceans. Both are also known to eat dead fish and some plant material.
|Behavior and Locomotion||G. geographica turtles are dormant from November through early April. Most of that time is spent under the water, wedged beneath submerged logs, in the bottom mud of a lake, or in a burrow. They have been known to change locations in the middle of the winter. Common map turtles are avid baskers and bask in groups. They are diurnal but sometimes forage at night; they are very wary and at the slightest hint of danger, they slip into the water and hide.|
|Conservation Status and Efforts||G. geographica turtles are least concern: they are rarely used as food and do not affect the fishing industry other than getting caught on hooks, as they do not eat game fish. However, they are less tolerant to poor conditions (e.g. pollution, waterfront development, and automobiles when they are migrating to breeding sites) than most other turtles. Common map turtles persist in suburban rivers and agricultural lands.
IUCN Red List Justification: While specific populations of Graptemys geographica have been impacted by habitat degradation and loss, exploitation or direct human-related mortality, currently the species is widespread, reasonably adaptable, and its mobility and reproductive potential appears sufficient to recover relatively rapidly (by turtle standards) from local population depletions. Thus, the species appears stable and secure in its conservation outlook for the foreseeable future, warranting Least Concern.
|Distribution||Throughout the eastern half of the US and northward into southeastern Canada.|
|Miscellaneous Information||Throughout the pet trade, Mississippi, common, and Ouachita map turtles were bred and hatched out by the thousands in the 1970s. Various other turtles were available, but as the salmonellosis Four-inch Law was established, map turtles and others slowly decreased in popularity. Today, these same three still hold the title for most common among the pet trade. Other species being captive-bred more often include the Texas map turtle, Cagle's map turtle, and the black-knobbed map turtle. Some harder-to-find map turtles include the yellow-blotched map turtle and the Pearl River map turtle|
Genus Trachemys (sliders)
Trachemys belongs to subfamily Deirochelyinae. The most famous type of slider is the red-eared slider, T. scripta elegans, a subspecies of the pond slider. Thus, the information below will be for the red-eared slider.
|Alternate names||Red-eared sliders are also known as red-eared terrapins.|
|Etymology||Small red stripes behind eyes, has an ability to slide off rocks and logs and into the water quickly, previously known as Troost’s turtle for Dutch-American herpetologist Gerard Troost|
|Physical Appearance||Size: Carapace can reach more than 40 cm (16 in), but the average length ranges from 15-20 cm (6-8 in).
Sexual dimorphism: Females are usually larger than males. Red-eared slider young look practically identical regardless of their sex. The shells of mature males are smaller than those of females and the red marks fade with age. Male red-eared sliders reach sexual maturity when their carapaces' diameters measure 10 cm (3.9 in) and females reach maturity when their carapaces measure 15 cm (6 in). Both male and females reach sexual maturity at five to six years. Males have longer claws on their front feet than the females which help them to hold on to a female during mating and is used during courtship displays. The male's tail is thicker and longer as it contains their dark coloured and retractable reproductive organ. The cloacal opening of the female is usually at or under the rear edge of the carapace while the male's opening occurs beyond the edge of the carapace. Males’ plastra are slightly concave, which helps to stabilize the male on the female’s carapace during mating, while females’ plastra are completely flat. Older males can sometimes have a dark greyish-olive green melanistic coloration with very subdued markings (red stripe may be difficult to see or absent). Females’ appearances are substantially the same throughout life.
Poikilotherms: Need to sunbathe frequently to warm themselves and maintain their body temperatures.
Shell: The upper carapace consists of: the vertebral scutes which form the central, elevated portion, the pleural scutes which are located around the vertebral scutes, and the marginal scutes which are around the edge of the carapace. The rear marginal scutes are notched. The scutes are bony keratinous elements. The carapace is oval and flattened (especially in the male) and has a weak keel that is more pronounced in the young. The color of the carapace changes depending on the age of the turtle. The plastron is spotted, in contrast to that of a painted turtle.
Color: The carapace usually has a dark green background with light and dark, highly variable markings. In young or recently hatched turtles, it is leaf green and gets slightly darker as a turtle gets older, until it is a very dark green, and then turns a shade between brown and olive green. The plastron is always a light yellow with dark, paired, irregular markings in the centre of most scutes. The plastron is highly variable in pattern. The head, legs, and tail are green with fine, irregular, yellow lines. The whole shell is covered in these stripes and markings that aid in camouflaging an individual.
Distinguishing features: Red stripe on each side of the head, which may lose color over time. Some individuals can also have a small mark of the same color on the top of their heads. Red-eared sliders do not have visible outer ears or external auditory canal: instead, they rely on middle ears entirely covered by cartilaginous tympanic discs.
|Life Cycle||Typically live 20-30 years though some have lived for more than 40 years. Shorter life expectancy when kept in captivity. Quality of their living environment has a strong influence on their lifespans and well being.
Eggs: Incubation takes 59 to 112 days. Late-season hatchlings may spend the winter in the nest and emerge when the weather warms in the spring. Just prior to hatching, the egg contains 50% turtle and 50% egg sac. A new hatchling breaks open its egg with its egg tooth, which falls out about an hour after hatching. This egg tooth never grows back. Hatchlings may stay inside their eggshells after hatching for the first day or two. If they are forced to leave the eggshell before they are ready, they will return if possible. When a hatchling decides to leave the shell, it still has a small sac protruding from its plastron. The yolk sac is vital and provides nourishment while visible, and several days later it will have been absorbed into the turtle's belly. The sac must be absorbed, and does not fall off. The split must heal on its own before the turtle is able to swim. The time between the egg hatching and water entry is 21 days. Damage to or inordinate motion of the protruding egg yolk, enough to allow air into the turtle's body, results in death. This is the main reason for marking the top of turtle eggs if their relocation is required for any reason. An egg turned upside down will eventually terminate the embryo's growth by the sac smothering the embryo. If it manages to reach term, the turtle will try to flip over with the yolk sac, which would allow air into the body cavity and cause death. The other fatal danger is water getting into the body cavity before the sac is absorbed completely and while the opening has not completely healed yet. The sex of red-eared sliders is determined by the incubation temperature during critical phases of the embryos' development. Only males are produced when eggs are incubated at temperatures of 22–27 °C (72–81 °F), whereas females develop at warmer temperatures. Colder temperatures result in the death of the embryos.
Breeding: Usually occurs between March and July. Takes place underwater.
Courtship: The male swims around the female and flutters or vibrates the back side of his long claws on and around her face and head (possibly to direct pheromones towards her). The female swims toward the male and (if she is receptive) sinks to the bottom for mating. Female may become aggressive towards the male if not receptive. Courtship can last 45 minutes but mating takes only 10 minutes. A male may appear to on occasion be courting another male and when kept in captivity may also show this behaviour towards other household pets, which could be a sign of dominance and may preclude a fight. Young turtles may carry out the courtship dance before they reach sexual maturity at five years of age (but they are unable to mate).
Egg laying: Females spend extra time basking after mating to keep her eggs warm and may also have changes of diet (eating only certain foods or not eating as much as they normally would). Females can lay between two and 30 eggs depending on body size and other factors. Females can lay up to five clutches in the same year. Clutches are usually spaced 12 to 36 days apart. Time between mating and egg-laying can be days or weeks. Actual egg fertilization takes place during the egg-laying which also permits the laying of fertile eggs the following season (as the sperm can remain viable and available in the female's body in the absence of mating). Females spend less time in the water in the weeks before egg laying. A female smells and scratches at the ground (indicating she is searching for a suitable place to lay her eggs), excavates a hole using her hind legs, and lays her eggs in it.
|Ecology, Habitat and Diet||Habitat: Inhabit areas with a source of still, warm water, such as ponds, lakes, swamps, creeks, streams, or slow-flowing rivers. Live in areas of calm water where they are able to leave the water easily by climbing onto rocks or tree trunks so they can warm up in the sun. Often found sunbathing in a group or even on top of each other. Also require abundant aquatic plants (as these are the adults' main food, although they are omnivores). Always remain close to water unless they are searching for a new habitat or when females leave the water to lay their eggs.
As an invasive species: Invasive red-eared sliders cause negative impacts in ecosystems. They have advantages over natives, including a lower age at maturity, higher fecundity or fertility rates, and a larger body size which gives them a competitive advantage at basking and nesting sites. They exploit food resources, transmit diseases and parasites, produce more offspring, are more aggressive and out-compete in food and nesting and basking sites), displace other turtle species, and eat plants as well as animals, so they could also have a negative impact on a range of native aquatic species (including rare frogs). A malaria-like parasite was spread to two wild turtle populations in Lane Cove River, Sydney.
|Behavior and Locomotion||Almost entirely aquatic. Leave water to sunbathe.
Dormancy: Occasionally rise to the surface for food or air, can occur to varying degrees. Usually become dormant over the winter at the bottoms of ponds or shallow lakes but have also been found under banks and rocks and in hollow stumps. Generally become inactive in October (when temperatures fall below 10 °C or 50 °F). Enter a state of sopor (do not eat or defecate, remain nearly motionless, frequency of their breathing falls). Can become active in warmer winter climates and come to the surface for basking. Quickly return to dormant state when the temperature begins to drop again. Generally come up for food in early March to as late as the end of April. Can survive anaerobically for weeks (producing ATP from glycolysis). Metabolic rate drops dramatically with heart rate and cardiac output dropping by 80% to minimise energy requirements. Lactic acid produced is buffered by minerals in the shell, which prevents acidosis. Red-eared sliders kept captive indoors should not undergo dormancy.
|Conservation Status and Efforts||On IUCN’s list of the 100 most invasive species (invasive in eastern Australia).
Invasive species: Red-eared sliders have been released or escaped into the wild in many parts of the world because of their popularity as a pet. Feral populations are now found in Australia, Europe, South Africa, the Caribbean Islands, Israel, Bahrain, the Mariana Islands, Guam, and southeast and far-east Asia. In Australia, it is illegal for members of the public to import, keep, trade, or release red-eared sliders, as they are regarded as an invasive species. Their import has been banned by the EU as well as specific EU member countries. In 2015 Japan announced it was planning to ban the import of red-eared sliders, but it would probably not take effect until 2020. In Australia, breeding populations have been found in New South Wales and Queensland, and individual turtles have been found in the wild in Victoria, the Australian Capital Territory and Western Australia. The Queensland government has invested close to $1 million AUD in eradication programs to date. There have been varying degrees of action by state governments to date, from ongoing eradication efforts by the Queensland government to very little action by the government of New South Wales. Experts have ranked the species as high priority for management in Australia and are calling for a national prevention and eradication strategy, including a concerted education and compliance program to stop the illegal trade, possession and release of slider turtles. Some states have other laws and regulations regarding possession of red-eared sliders because they can be an invasive species where they are not native and have been introduced through the pet trade. Now, it is illegal in Florida to sell any wild-type red-eared slider, as they interbreed with the local yellow-bellied slider population (T. s. scripta). Unusual color varieties such as albino and pastel red-eared sliders (from captive breeding) can still be sold.
As a pet: World’s most commonly traded reptile (relatively low price, small size, easy maintenance). As with other turtles, tortoises, and box turtles, individuals that survive their first year or two live generally around 30 years. Infection risk. Can inflict painful bites when mature. Many are dumped into the wild when mature with negative ecological, social and economic impacts.
As a Salmonella carrier: The turtle may also have significant public health costs due to the impacts of turtle-associated salmonella on human health. Outbreaks in multiple states and fatalities in children, associated with handling salmonella-infected turtles, have been recorded in the USA. Salmonella can also spread to humans when turtles contaminate drinking water. They are asymptomatic carriers of Salmonella. This has given rise to justifiable concerns given the many instances of infection of humans caused by the handling of turtles, which has led to restrictions in the sale of red-eared sliders in the USA. A 1975 (FDA) regulation bans the sale of both turtle eggs and turtles with a carapace length of less than 4 in (10 cm) except "for bona fide scientific, educational, or exhibition purposes, other than use as pets." This regulation comes under the Public Health Service Act, and is enforced by the FDA in cooperation with state and local health jurisdictions. Turtles and turtle eggs found to be offered for sale in violation of this provision are subject to destruction in accordance with FDA procedures. A fine of up to $1,001 and/or imprisonment for up to one year is the penalty for those who refuse to comply with a valid final demand for destruction of such turtles or their eggs. Wash hands immediately after playing with the turtle, feeding it, or changing its water.
|Distribution||United States to northern Argentina, originated from the area around the Mississippi River and the Gulf of Mexico in warm climates in the southeastern United States, native areas range from the southeast of Colorado to Virginia and Florida|
|Miscellaneous Information||Haugrud’s slider turtle, T. haugrudi, is extinct. The Teenage Mutant Ninja Turtles were revealed as red-eared slider turtles in the second volume of the Tales of the Teenage Mutant Ninja Turtles which led to a pet craze in Great Britain and subsequent ecological havoc as they were accidentally or deliberately released in the wild|
Genus Chrysemys (painted turtles)
Chrysemys belongs to the subfamily Deirochelyinae and is a monotypic genus, with C. picta as its only species. It has four subspecies, C. p. picta (eastern), C. p. marginata (midland), C. p. dorsalis (southern), and C. p. bellii (western), which intergrade, or blend together, at range boundaries.
|Alternate names||Skilpot (East Coast)|
|Etymology||Chrysemys comes from Ancient Greek for gold (chryso) and freshwater tortoise (emys). pictus is Latin for colored. Skilpot from the Dutch for turtle (schildpad).|
|Physical Appearance||The adult painted turtle female is 10–25 cm (4–10 in) long; the male is smaller. The turtle's top shell is dark and smooth, without a ridge. Its skin is olive to black with red, orange, or yellow stripes on its extremities. The subspecies can be distinguished by their shells: the eastern has straight-aligned top shell segments; the midland has a large gray mark on the bottom shell; the southern has a red line on the top shell; the western has a red pattern on the bottom shell.
Shell: The painted turtle's shell is long, oval, smooth with little grooves where the large scale-like plates overlap, and flat-bottomed. One of the most colorful turtles is the eastern painted turtle, which includes a yellow plastron and a black or olive shell with red markings around the rim.
Color: The carapace varies from olive to black. Darker specimens are more common where the bottom of the water body is darker. The plastron is yellow, sometimes red, sometimes with dark markings in the center. Similar to the top shell, the turtle's skin is olive to black, but with red and yellow stripes on its neck, legs, and tail. As with other pond turtles, such as the bog turtle, the painted turtle's feet are webbed to aid swimming.
Distinctive features: The head of the turtle is distinctive. The face has only yellow stripes, with a large yellow spot and streak behind each eye, and on the chin two wide yellow stripes that meet at the tip of the jaw. The turtle's upper jaw is shaped into an inverted "V" (philtrum), with a downward-facing, tooth-like projection on each side. The painted turtle is similar to the red-eared slider except that it is flatter.
Sexual dimorphism: The adult female is generally longer than the male, 10–25 cm (4–10 in) versus 7–15 cm (3–6 in). For a given length, the female has a higher (more rounded, less flat) top shell. The female weighs around 500 g (18 oz) on average, against the males' average adult weight of roughly 300 g (11 oz). The female's greater body volume supports her egg-production. The male has longer foreclaws and a longer, thicker tail, with the cloaca located further out on the tail.
C. p. picta: Males are 13–17 cm (5–7 in) long. Females are 14–17 cm (6–7 in). Upper shell is olive green to black and may possess a pale stripe down the middle and red markings on the periphery. Carapace scutes have pale leading edges and occur in straight rows across the back (unlike all other North American turtles, including the other three subspecies of painted turtle, which have alternating segments). Plastron is plain yellow or lightly spotted, sometimes as few as one dark grey spot near the lower center of the shell.
C. p. marginata: 10–25 cm (4–10 in) long. centrally located midland is the hardest to distinguish from the other three subspecies, bottom shell has a characteristic symmetrical dark shadow in the center which varies in size and prominence
C. p. dorsalis: 10–14 cm (4–6 in) long. Top stripe is a prominent red. Plastron is tan and spotless or nearly so.
C. p. bellii: Up to 26.6 cm (10 in) long. Carapace has a mesh-like pattern of light lines. Top stripe present in other subspecies is missing or faint. Bottom shell has a large colored splotch that spreads to the edges (further than the midland) and often has red hues.
|Life Cycle||The turtles mate in spring and autumn. Females dig nests on land and lay eggs between late spring and mid-summer. Hatched turtles grow until sexual maturity: 2–9 years for males, 6–16 for females. Adults in the wild can live for more than 55 years. The hatchling has a proportionally larger head, eyes, and tail, and a more circular shell than the adult.
Breeding: The painted turtles mate in spring and fall in waters of 10–25 °C (50–77 °F). Males start producing sperm in early spring, when they can bask to an internal temperature of 17 °C (63 °F). Females begin their reproductive cycles in mid-summer, and ovulate the following spring. Courtship begins when a male follows a female until he meets her face-to-face. He then strokes her face and neck with his elongated front claws, a gesture returned by a receptive female. The pair repeat the process several times, with the male retreating from and then returning to the female until she swims to the bottom, where they copulate. As the male is smaller than the female, he is not dominant. The female stores sperm, to be used for up to three clutches, in her oviducts; the sperm may remain viable for up to three years. A single clutch may have multiple fathers. Nesting is done, by the females only, between late May and mid-July. The nests are vase-shaped and are usually dug in sandy soil, often at sites with southern exposures. Nests are often within 200 m (220 yd) of water, but may be as far away as 600 m (660 yd), with older females tending to nest further inland. Nest sizes vary depending on female sizes and locations but are about 5–11 cm (2–4 in) deep. Females may return to the same sites several consecutive years, but if several females make their nests close together, the eggs become more vulnerable to predators. The female's optimal body temperature while digging her nest is 29–30 °C (84–86 °F). If the weather is unsuitable, for instance a too hot night in the Southeast, she delays the process until later at night. Painted turtles in Virginia have been observed waiting three weeks to nest because of a hot drought. While preparing to dig her nest, the female sometimes exhibits a mysterious preliminary behavior. She presses her throat against the ground of different potential sites, perhaps sensing moisture, warmth, texture, or smell, although her exact motivation is unknown. She may further temporize by excavating several false nests as the wood turtles (Glyptemys insculpta) also do. The female relies on her hind feet for digging. She may accumulate so much sand and mud on her feet that her mobility is reduced, making her vulnerable to predators. To lighten her labors, she lubricates the area with her bladder water. Once the nest is complete, the female deposits into the hole. The freshly laid eggs are white, elliptical, porous, and flexible. From start to finish, the female's work may take four hours. Sometimes she remains on land overnight afterwards, before returning to her home water. Females can lay five clutches per year, but two is a normal average after including the 30–50% of a population's females that do not produce any clutches in a given year. In some northern populations, no females lay more than one clutch per year. Bigger females tend to lay bigger eggs and more eggs per clutch. Clutch sizes of the subspecies vary, although the differences may reflect different environments, rather than different genetics. The two more northerly subspecies, western and midland, are larger and have more eggs per clutch—11.9 and 7.6, respectively—than the two more southerly subspecies, southern (4.2) and eastern (4.9). Within subspecies, also, the more northerly females lay larger clutches.
|Ecology, Habitat and Diet||Habitat: Slow-moving fresh waters
Symbiosis: Western painted turtles help disperse white water-lily seeds (turtles consume the hard-coated seeds which remain viable after passing through the turtles and disperse them through their feces)
Predators: Painted turtles are most vulnerable to predators when young. Nests are frequently ransacked and the eggs eaten by plains garter snakes, crows, chipmunks, thirteen-lined ground and gray squirrels, skunks, groundhogs, raccoons, badgers, gray and red fox, and humans. The small and sometimes bite-size, numerous hatchlings fall prey to water bugs (e.g. water scorpions), bass, catfish, bullfrogs, snapping turtles, three types of snakes (copperheads, racers and water snakes), herons, rice rats, weasels, muskrats, minks, and raccoons. As adults, the turtles' armored shells protect them from many potential predators, but they still occasionally fall prey to alligators, ospreys, crows, red-shouldered hawks, bald eagles, and especially raccoons. Painted turtles defend themselves by kicking, scratching, biting, or urinating. In contrast to land tortoises, painted turtles can right themselves if they are flipped upside down.
Diet: Omnivorous: Eat aquatic vegetation (e.g. duckweed at water surface and American water lily), algae, and small water creatures including insects (e.g. dragonfly larvae), crustaceans (e.g. crayfish), and fish. Hunt along water bottoms. Quickly jut their heads into and out of vegetation to stir potential victims out into the open water where they are pursued. Hold large prey in its mouth and tear prey apart with forefeet. Skims surface of water with its mouth open to catch small particles of food.
C. p. picta: Prefer to eat in water but have been observed eating on land. Fish consumed are typically injured or dead.
C. p. marginata: Most aquatic insects and vascular and nonvascular plants.
C. p. dorsalis: Changes with age. Juveniles eat 13% vegetation. Adults eat 88% vegetation. Perhaps shows that the turtle prefers small larvae and other prey but can only obtain significant amounts while young. Reversal of feeding habits with age has also been seen in the false map turtle which inhabits some of the same range. Most common plants eaten by adults are duckweed and algae. Most common prey items are dragonfly larvae and crayfish.
C. p. bellii: Consumption of plants and animals changes seasonally. Eats 60% insects in early summer. Eats 55% plants in late summer.
|Behavior and Locomotion||Reliant on warmth from its surroundings, the painted turtle is active only during the day when it basks for hours on logs or rocks. During winter, the turtle hibernates, usually in the mud at the bottom of water bodies.|
|Conservation Status and Efforts||While habitat loss and road killings have reduced the turtle's population, its ability to live in human-disturbed settings has helped it remain the most abundant turtle in North America.|
|Distribution||Most widespread native turtle of North America, from southern Canada to Louisiana and northern Mexico, from Atlantic to Pacific.|
|Miscellaneous Information||Existed 15 mya (Neogene period). The four subspecies evolved during the last ice age. Played the part of a trickster in the traditional tales of Algonquian tribes. Four U.S. states have named the painted turtle their official reptile.|
Genus Pseudemys (cooters and redbellies)
Pseudemys belongs to the subfamily Deirochelyinae, and there are seven species, some of which the validity remains in question:
- P. alabamensis, the Alabama red-bellied cooter;
- P. concinna, the river cooter, split up into the subspecies
- P. c. concinna, the Eastern river cooter,
- P. c. floridiana, the coastal plain/Florida cooter, and
- P. c. suwanniensis, the Suwannee cooter;
- P. gorzugi, the Rio Grande cooter;
- P. nelsoni, the Florida red-bellied cooter;
- P. peninsularis, the peninsula cooter;
- P. rubriventris, the northern red-bellied cooter; and
- P. texana, the Texas river cooter.
|Etymology||Cooters from kuta (the word for turtle in Bambara and Malinké), brought to America by African slaves. The specific name gorzugi is in honor of George R. Zug, Curator of Amphibians and Reptiles, National Museum of Natural History. The specific name nelsoni is in honor of American biologist George Nelson (born 1873).|
|Physical Appearance||Among the largest of the family Emydidae, with carapaces up to 44 cm (17.3 in) and weighing up to 10 kg (22 lb).
|Life Cycle||See table:
|Ecology, Habitat and Diet||See table:
|Behavior and Locomotion||All are aquatic and can easily be seen basking on rocks on logs in sunny weather.
|Conservation Status and Efforts||See table:
|Distribution||Eastern US and northeastern Mexico.
|Miscellaneous Information||P. alabamensis is the state reptile of Alabama. In captivity, river cooters (P. concinna) need an aquatic habitat, with a dry basking area. They need a warming light and UVB radiation (from reptile lights or direct sunshine). As juveniles, they can be kept in a 20- or 30-gallon long tank, but they will outgrow those accommodations, and need a very large tank or outdoor pond.|
Genus Clemmys (spotted turtle)
Clemmys belongs to the subfamily Emydinae and has one species, C. guttata. Originally, Clemmys had four species, but they have since been moved (the bog turtle, Glyptemys muhlenbergii, the spotted turtle C. guttata, the western pond turtle Actinemys marmorata, and the wood turtle Glyptemys insculpta).
|Etymology||Clemmys was first named in 1828 by Ferdinand August Maria Franz von Ritgen. Johann Gottlob Schneider originally described the species as Testudo guttatai in 1792; however, he is now the authority for the current binomial name, Clemmys guttata.|
|Physical Appearance||Size: Reach a carapace length of 8-12 cm (3.1-4.7 in) but generally 3.5-12.5 cm (1.4-4.9 in).
Carapace: Black to bluish black. Contains anywhere from zero to about one hundred tiny yellow round spots (defining characteristic). Left side may have more spots than right side. Spotting patterning extends from the head to the neck and out onto the limbs. Broad, smooth, and low with no keel.
Plastron: Yellow or orange-yellow. Black spot present on each scute. Melanism increases with age until entire surface is black.
Sexual dimorphism: Can be told apart from birth: differences in shell heights (females are taller), body masses (females are heavier), size (females are larger), plastra (females’ are longer), chin coloration (females have yellow, males have tan), eye coloration (females have orange, males have brown), tail length (females’ are short, males’ are long and thick), plastron shape (flat or convex in females, concave in males), and spots (females have more spots on average).
Body: Spots on head, neck, and limbs. Head is black. Upper jaw is notched. Large orange blotch on each side of head. Several yellow bands of varying size. Dorsal skin is black with sparse yellow spots. Ventral skin may be brighter: orange, pink, or red. These lightly pigmented areas do vary geographically. Tails of some individuals have yellow striping. More southern individuals tend to have smaller and less conspicuous spots.
Karyotype: 50 chromosomes.
|Life Cycle||Hatchlings resemble the adults closely (each segment of the upper shell consistently has only one yellow spot). The females during times of nesting will travel onto land and lay eggs on sunny soil. Nesting also may take place in other terrestrial locations, for instance near man-made dykes or the nest of a muskrat. Sex determined by temperature during embryonic development.|
|Ecology, Habitat and Diet||Habitat: Semi-aquatic. A variety of shallow, freshwater habitats including swamps, bogs, fens, marshes, woodland streams, flooded forests and wet pastures. Also, brackish streams that are influenced by tides can also serve as a home to this turtle in addition to ditches, vernal pools, and sedge meadows. For a habitat to be sufficient for spotted turtle survival it must have clear and clean water, areas of soft substrate, and aquatic or emergent vegetation. An optimum habitat would include shallow and slow moving waters with soft muddy soil, sedge tussocks, water lilies, sphagnum moss, and cattails. Because it is so often found in areas that contain duckweed, the yellow spots on these turtles may serve as a form of camouflage. The spotted turtle avoids artificial reservoirs and deep, open-water areas. In a study where radio-telemetry was used, spotted turtle behavior was observed in northeastern America, where distinct seasonal movement patterns revealed that spotted turtles exhibited a positive association in wetlands hosting abundant Wood Frog egg masses in spring and from spring to late summer, a negative association in forested wetlands was detected.
Predators: Many specimens will show mutilation injuries and scars from past predation attempts. Raccoons (Procyon lotor) are particularly adept at consuming and killing this species. Muskrats kill many spotted turtles during the winter dormant period.
Diet: Active hunter. Seeks out prey in water by pointing head into aquatic plants. Feeds at temperatures above 14.2 °C (57.6 °F) (roughly the middle of March to September). Omnivorous. Eats exclusively in the water. Consumed alive or dead. Eats aquatic vegetation, green algae, wild cranberries (in at least one instance), aquatic insect larvae, worms, slugs, millipedes, spiders, crustaceans, tadpoles, salamanders, and several genera of small fish. Some of the insects commonly found in with the spotted turtle's stomach contents are terrestrial, suggesting the turtle moves onto land to hunt. Will eat fruits such as cantaloupe and watermelon and fresh and canned fish in captivity.
|Behavior and Locomotion||Can be decidedly terrestrial, spending a good amount of time on land and sometimes basking on patches of grass near its body of water. Spotted turtles home ranges tend to occupy limited areas of about 0.5 to 3.5 hectares (1.2 to 8.6 acres). Spotted turtles have been observed to dive into the water and bury themselves in the bottom mud when surprised while basking.
Dormancy: During the freezing temperatures of winter and the extreme heat of summer, spotted turtles become inactive during environmentally unfavorable conditions. However, the species appears to be relatively tolerant of drought conditions. Spotted turtles do become active very early in the spring, and are often active at relatively cold water temperatures during that season. Activity appears to peak during April and May in the northern part of the range. In the warmest part of the summer (when water temperatures exceed 30 °C), they may aestivate terrestrially or aquatically for long periods of time. During summer dormancy, the turtles may burrow into leaf litter in woodlands or marsh edges or open fields; others remain in muskrat burrows or other aquatic refuges. Litzgus and Brooks (2000) have questioned the common presumption that summer dormancy is an attempt by the turtles to avoid high temperatures; data from Ontario and elsewhere suggests that avoidance of predation and conservation of energy resources may be viable alternate explanations. No matter the explanation for dormancy, the "winter" dormant period may commence in late summer or fall, but in almost every instance after a return to aquatic habitats. They are only active in the cooler spring months.
|Conservation Status and Efforts||Mitigation requires spatial and temporal shifts in habitat use
Status: In Canada, the spotted turtle is federally endangered, while in the United States the spotted turtle is currently under review by the Fish and Wildlife Service for protection under the Endangered Species Act. It is listed by the IUCN as endangered, and has "listed" status in many of the states where it occurs. For example, in Indiana the spotted turtle is listed as an endangered species. In the Northeast, it has protective status in five of the six New England states and is listed as a species of special concern in New York. There is a high risk of extinction in several ranging from South California up to Maine and Ontario. The turtles lack safe, navigable corridors to connect them to important habitat or other populations. They have experienced a 50% reduction in habitat. The Center for Biological Diversity petitioned the U.S. Fish and Wildlife Service to protect the spotted turtle under the Endangered Species Act in 2012. In June 2015 the petition received an initial positive finding that the species may qualify for protection. Another Center petition resulted in protections for the spotted turtle under the Convention on International Trade in Endangered Species in 2013.
Threats: Habitat destruction and alteration, collection for the pet trade, and other human impacts such as vehicle mortality (cars and mowers) are leading to declines in populations. Spotted turtles require frequent terrestrial movements for their diverse habitat requirements which exposes them to potential threats including unsustainable sources of adult mortality such as road kill and illegal collection. They are declining throughout North America due to habitat loss and poaching.
|Distribution||The spotted turtle ranges from southern Maine, Quebec, and Ontario, south along the eastern US to Florida in the east and central Indiana and Ohio in the west. Disjunct populations exist in the Canadian portion of its range and also in central Illinois, central Georgia, North Carolina, South Carolina, and Indiana. In Indiana and Illinois, the species is found only in the northern portion of the state but it is found on most of the lower peninsula of Michigan. The highly fragmented distribution of spotted turtles in Ohio only covers the northern two-third of the state. Although the spotted turtle has been observed in Quebec, no permanent population is known to exist there. However, 104 populations have been discovered in Ontario. Most of these concentrated around Georgian Bay, on the north shore of Lake Erie, and southeastern Ontario. Of the original 104 sites noted, 36 are known to no longer have spotted turtles. Despite the seemingly large number of populations in Canada, many are not self-sustaining because of the following reasons: the majority of the populations are small, they all have less than 200 individuals, and the areas are all isolated from one another. All told it is estimated that anywhere from 1000 to 2000 spotted turtles live in Canada however, with individual populations ceasing to exist, this number is declining. The spotted turtle's range overlaps that of many other turtles. It can often be found in the same wetlands as wood turtles, bog turtles, snapping turtles, painted turtles, Blanding's turtles, eastern box turtles, common musk turtles, and eastern mud turtles.|
|Miscellaneous Information||Shed their scutes in small pieces (occasionally resulting in completely smooth shelled specimens). Very intelligent (brain capacity of a mouse). Tested like wood turtles in mazes.|
Genus Glyptemys (sculptured turtles - wood and bog turtles)
Glyptemys belongs to the subfamily Emydinae and comprises two species (the wood turtle G. insculpta and the bog turtle G. muhlenbergii). This genus used to belong to Clemmys. There are no recognized wood turtle subspecies although there are morphological differences between areas.
|Alternate names||Wood turtles: Red-legged tortoises, redlegs
Bog turtles: Testudo muhlenbergii, Emys muhlenbergii, Calemys muhlenbergii, Clemmys muhlenbergii, Emys biguttata, Clemmys nuchalis, yellowheads, snappers, Muhlenberg's turtles, red neck turtles
|Etymology||Glyptemys comes from glyp (carved) and emys (turtle).
Wood turtles: Common and specific names refer to the rough and sculptured surface of the carapace.
Bog turtles: The specific name muhlenbergii is in honor of Reverend Gotthilf Heinrich Ernst Muhlenberg (the 18th century botanist from Pennsylvania who first found this turtle in his millpond).
|Physical Appearance||Wood turtles:
|Life Cycle||Wood turtles live for up to 40 years in the wild and 58 years in captivity when unharmed. Bog turtles live for an average of 20-30 years in the wild.
Wood turtle breeding: Oviparous. Do not provide parental care outside of nest-building. The location and quality of nesting sites determine the offspring survival and fitness. Females invest significant time and energy into nest site selection and construction. Females select nest sites based on soil temperature (preferring warmer temperature nest sites) but not soil composition. Average nest size is four inches wide and three inches deep. Also, females build nests in elevated areas in order to avoid flooding and predation. After laying eggs, female wood turtles will cover the nest with leaves or dirt in order to hide the unhatched eggs from predators, and then the female leaves the nest location until the next mating season. Nesting sites can be used by the same female for multiple years. Because nest building occurs along rivers, females tend to spend more time along river areas, compared to male turtles.
Bog turtle breeding: One clutch per year (average of three or four eggs each). Young tend to grow rapidly (reach sexual maturity between 4 and 10). Juvenile carapace is round and dark brown (usually with a conspicuous keel). Yellow plastron with a large black blotch in the center. Bright orange patch behind the eye is present at hatching. Mating occurs in late April to early June in shallow water and on land. Mating is similar to that described for wood turtles, with the male clinging tightly to the edge of the female's carapace and juxtaposing his tail beneath hers; shell pounding has not been observed. Size at maturity in a Pennsylvania population was 70 mm PL at an age of 6 years for both sexes. Eggs are laid in May to July in shallow nests in grass tussocks, moss, or soft soils. Laboratory incubation time for one clutch was 46 days (unknown for natural populations). Only known hatching date for a Virginia clutch is 4 August. Most hatching occurs in August, but emergence may be delayed until October or the following April or May. Twin embryos from a single North Carolina egg were reported.
|Ecology, Habitat and Diet||Wood turtles:
|Behavior and Locomotion||Wood turtles: Diurnal. Not overtly territorial. Dormant in winter. Estivates in hottest parts of summer. Decidedly more terrestrial in the east, especially during the summer when they can be found in wooded areas with wide open canopies. However, even here, they are never far from water and will enter it every few days.
Bog turtles: Diurnal. Secretive. Spends most of time buried in mud. Dormant in winter. Bask during midday on grass mats or in shallow rivulets. Feeding and searching for prey happens in morning and late afternoon. More active during cloudy days. Escape potential predation by turning themselves on end and diving on soft mud (swimming through it as if it were water). Not aggressive.
|Conservation Status and Efforts||Wood turtles are endangered. Bog turtles are critically endangered (protected under ESA). The Bronx Zoo has successfully bred BTs in captivity since 1973. Legally protected in some states. Endangered under Virginia law.
Wood turtle threats: Humans cause a large number of deaths through habitat destruction and fragmentation (negatively impact ability to search for mates and build high quality nests), road traffic, farming accidents, and illegal collection.
Bog turtle threats: Demand for the bog turtle is high in the black market pet trade, partly because of its small size and unique characteristics. Several individuals are poached.
|Distribution||Endemic to North America.
Wood turtles: Extends from Nova Scotia to the northeast to Minnesota in the west and Virginia in the south. Forced south by encroaching glaciers in the past (skeletal remains found as far south as Georgia). Most New England states. Disjunct with populations often being small and isolated. Roughly 30% of total population in Canada.
Bog turtles: Vermont in north, south to Georgia, west to Ohio.
|Miscellaneous Information||Genetically and morphologically related to spotted turtle (Clemmys guttata). In the past, wood turtle populations were forced south by extending glaciers. Remains from the Rancholabrean period (300,000 to 11,000 years ago) have been found in states such as Georgia and Tennessee, both of which are well south of their current range. After the receding of the ice, wood turtle colonies were able to re-inhabit their customary northern range (areas like New Brunswick and Nova Scotia). Small and colorful, generally easy to keep, and respond well to behavioral conditions, which make them sought-after pets.|
Genus Deirochelys (chicken turtle)
Deirochelys belongs to the subfamily Deirochelyinae and has one species, D. reticularia, which has three subspecies, the eastern chicken turtle D. r. reticularia, the Florida chicken turtle D. r. chrysea, and the western chicken turtle D. r. miaria.
|Alternate names||American snake necks|
|Etymology||Chicken turtles taste like chicken.|
|Physical Appearance||Similar in appearance to the eastern painted turtle (Chrysemys picta picta)
Distinctive features: An unusually long neck that is close to the length of plastron (up to 80% of carapace) and striped with yellow. A yellow stripe on both the forelegs and rear legs.
Adaptations: Webbed feet to help it swim.
Shell: Pale-yellowish net-like pattern on carapace. Pear-shaped carapace that is olive to dark brown. Plastron is usually solid yellow and unmarked.
Sexual dimorphism: Females usually larger than the males. Males have a bigger, longer tail. Males have longer front claws. Males have more compressed shells.
Size: 15-23 cm (6-9 in). Up to 25 cm (10 in). Typical adult ranges from 15.3-17.8 cm (6-7 in). Medium in size compared to other turtles.
|Life Cycle||Wild chicken turtles have been recaptured up to 15 years after their first capture. Some reached the known maximum ages of 20 to 24 years. Shorter life history than many other turtles in Georgia.
Breeding: Males reproduce with female chicken turtles by vibrating the fore-claws against the female's face. Once the female is receptive, copulation occurs. Chicken turtles are different from most other North American turtles because they nest in late summer, fall, or winter. In South Carolina, there are two-egg laying seasons; from winter to early spring (February to may) and fall to early winter (August to November). Females excavate cylindrical nest on land in a variety of soil types, from sandy to heavy soils.
Eggs: Females lay 2 to 19 clutches of eggs. Chicken turtle embryos go through a period of diapause in the late gastrula stage. They must experience a period of cool temperatures before development proceeds. Eggs hatch in 152 days at 29 Celsius in South Carolina, and some eggs may overwinter in the nest before hatching. They can emerge a year or more after the eggs were laid in Georgia. Incubation temperature influences the sex of the embryos, with a 25 degrees Celsius incubation temperature resulting in all males. Warmer temperatures result in an increase in female embryos, with only 11 percent becoming males at incubation temperatures of 30 degrees Celsius. Chicken turtles are 2.5 cm (1 in) in diameter at birth.
|Ecology, Habitat and Diet||Habitat: Chicken turtles are semi-aquatic turtles, found both in water and on land. They prefer quiet, shallow, and still bodies of water such as shallow ponds and lakes, ditches, marshes, cypress swamps, and Carolina bays. They prefer water with dense vegetation and soft substrate (e.g. seasonal wetlands with abundant vegetation). Chicken turtles are tolerant of ephemeral aquatic habitats (made up of plants with short life cycles) and readily travel onto land to burrow into the soil and escape dry conditions. They have been found at depths of a few centimeters to more than 2 m. They are generally absent from large permanent ponds and reservoirs.
Predators: Eastern moles (Scalopus aquaticus) are significant predators of chicken turtle nests. Raccoons (Procyon lotor) and snapping turtles (Chelydra serpentina) are potential predators. Chicken turtles are both predator and prey.
Diet: Chicken turtles are omnivorous, eating crayfish, small fish, fruits, insects, invertebrates, frogs, tadpoles, and plants. During the first year of their lives, they are almost completely carnivorous. Although they are mostly carnivorous at birth, they still eat plants. The chicken turtles uses its well-developed hyoid apparatus to create suction that pulls food items into its throat, which is very unusual. Chicken turtles impact populations of aquatic insects, crustaceans, tadpoles, and aquatic vegetation.
|Behavior and Locomotion||Chicken turtles are regularly encountered on land, migrating between aquatic habitats or seeking areas to burrow into the soil and escape dry conditions. Males generally travel around farther than females. They are social, spending much of their time basking on logs and rocks and swim in small groups. Chicken turtles become dormant in the soft mud, but only in the northern part of their range, and vegetation of bodies of water. They are known to be timid but if caught they generally will bite very easily. They spend most of their time in the water. They are among the most territorial of turtles. Nearly all males and some females leave the wetland each fall to spend the winter buried in the forest. Chicken turtles estivate during drought in uplands rather than migrating to other wetlands.|
|Conservation Status and Efforts||Chicken turtle populations are currently considered stable throughout their range, although they do face potential threats. The eastern chicken turtle species is listed as state threatened in Virginia. Habitat destruction reduces suitable habitat for foraging, migration, and brumation. Chicken turtles are sometimes killed on roads as they migrate between habitats. Hunting for food impacts populations of chicken turtles as well. Chicken turtles are potentially vulnerable to habitat loss and degradation. Much that is known about the ecology of chicken turtles comes from population studies conducted at the Savannah River Ecology Lab, particularly the work of Dr. Kurt Buhlmann. Chicken turtles have no special status in the IUCN Red List or CITES.|
|Distribution||Coastal areas from Virginia to Texas and northward into Oklahoma and Arkansas: D. r. chrysea is limited to peninsular Florida, and D. r. reticularia and D. r. miaria are separated by the Mississippi River.|
|Miscellaneous Information||Chicken turtle meat used to be popular in the southern US.|
Genus Emydoidea (Blanding’s turtles)
Emydoidea belongs to subfamily Emydinae and has one species, E. blandingii.
|Alternate names||Emys blandingii, semi-box turtle (although the plastron is hinged, the plastral lobes do not shut as tight as the box turtles' do)|
|Etymology||Both the specific name, blandingii, and the common name, Blanding's turtle, are in honor of American naturalist Dr. William Blanding (1773–1857).|
|Physical Appearance||Size: Average straight carapace length of ~18-23 cm (7.1-9.1 in) with a maximum of 25.5 cm (10.0 in).
Distinguishing features: Bright yellow chin and throat.
Shell: Carapace is domed but slightly flattened along the midline and is oblong when viewed from above. Carapace is speckled with numerous yellow or light-colored flecks or streaks on a dark background. Plastron is yellow with dark blotches symmetrically arranged.
Color: Head and legs are dark and usually speckled or mottled with yellow.
|Life Cycle||Based on the extreme lack of aging symptoms and lack of age related decline, these turtles are considered a negligibly senescent (degrading with age) species. Physically active and capable of reproduction into eight or nine decades of life. Can live more than 83 years. Mean time between generations ~37 years.
Breeding: Typically spring and early summer (March to early July) but has been observed from early March to November. Delayed sexual maturity. Females take ~14–20 years to reach sexual maturity with a mean of 17.5 years. Males of approximately 12 years old are sexually mature in Massachusetts. Individuals able to breed throughout their lives. Courtship consists of the following eight behaviors highlighted here:
Nesting: Begins in early June and lasts throughout the month. Females lay one clutch per year and may not reproduce some years. Polygynandrous. 81.2% of clutches in a Minnesota population were sired by multiple males, and the frequency of multiple paternity was among the highest recorded in males. Females store sperm for later use. There is female mate choice. Can make significant overland movements to reach nesting areas (ex. in a Minnesota population, one female was observed to travel over 1,900 m to nest). Nesting microsites tend to be those with well-drained soils (e.g. sandy or a mix of gravel and sand or gravelly loam). Prefer tilled substrates to those who have been mowed or weeded. Females dig a nest approximately 12 cm deep, covering the eggs with substrate and camouflaging the nest by smoothing the surface flat. No parental care.
Eggs: Clutch size differs geographically. Ranges from 5-11 eggs in Maine with an average of 8.5 and 3-19 in Michigan with an average of 10. Males produced at under 28 ℃. Females produced at over 30 ℃. Hatching is greatest at 26.5 ℃ and decreases around 30 ℃. Not tolerant of temperatures below 22 ℃. Relatively tolerant of dry conditions.
|Ecology, Habitat and Diet||Habitat: Its general habitat is wetlands with clean shallow water. It is known to bask on logs, and will wander far from water, particularly when nesting. It generally nests in sunny areas, with well drained soil. Younger turtles may bask on sedge and alder hummocks. Young will often travel far in search of mating sites, new habitat, or new food sources, as do elder turtles. In New York, Blanding’s turtles occupy habitats with:
Ideally, there is a “habitat complex” that provides all wetland and upland habitat types used during springtime, breeding, nesting, summer, and dormancy activities in close proximity to each other. Springtime foraging and basking habitat consisting of deep, fluctuating pools represents important habitat for Blanding’s turtles (Kiviat 1993). The use and importance of small isolated wetlands, such as vernal pools and kettle ponds, apart from their larger permanent core wetlands, by Blanding’s turtles cannot be overstated. Several studies have shown that these wetlands are important for both juveniles and adults to forage on ephemeral food sources such as tadpoles and aquatic insect nymphs and larva (Pappas et al. 2000, Piepgras and Lang 2000, Ross and Anderson 1990, Butler and Graham 1995, Congdon et al. 2003). Females also visit small wetlands to rehydrate during the nesting period. Blanding’s turtles have been documented to make movements greater than 1km from resident wetlands to visit these smaller wetlands (Congdon et al. 2003).
Predators and parasites: Adult Blanding’s turtles have very few natural predators. However, like other species of turtles, Blanding’s turtles experience high rates of nest predation, with some nestlings experiencing mortality from causes not fully recognized. Of nine protected nests that were located at a site in northern New York, two did not hatch and six of the seven remaining contained some eggs (53% or 5.2 per nest) that did not hatch (Johnson and Crocket 2009). At the northeastern edge of the range in Nova Scotia, nest productivity varied by year, presumably due to changes in weather patterns (Standing et al. 1999). Standing et al. (1999) observed that 76% and 93% of nests produced at least one young in 1994 and 1995, respectively, yet only 18% of protected nests were productive in 1996. Congdon et al. (1983) measured rates of nest predation that ranged from 42-93% in a Michigan population. In addition, 84% of nest predation occurred within the first five days after laying, with 42% occurring during the first 24 hours after laying (Congdon et al. 1983). In Wisconsin, 59% of nests were depredated within the first two weeks of being laid (Reid et al. 2010). Temple (1987) found that turtle nests that were within 50 m of a habitat edge were significantly more likely to be depredated than interior nests. In addition, Reid et al. (2015) found that nests closer to forested edges were more likely to be depredated. Predators such as raccoons, foxes, skunks, and other mesocarnivores are common nest predators (Ernst and Lovich 2009). Ants (Congdon et al. 1983) and even plant root intrusion (Congdon et al. 2000) may reduce nest and hatching success as well. Once nestlings hatch and emerge from nests, predators such as skunks (Mephitis mephitis), raccoons (Procyon lotor), coyotes (Canis latrans), foxes (Vulpes and Urocyon cinereoargentatus), and crows (Corvus brachyrynchos) prey on hatchlings (Ernst and Lovich 2009). American kestrels (Falco sparverius) have also been reported to prey on hatchlings in Massachusetts (Ernst and Lovich 2009). Leeches (Placobdella ornata, P. parasitica) parasitize both juveniles and adults (Bolek 2001). In addition, Sarcophagid fly larvae were found in a very high percentage of Blanding’s turtle nests in southeastern Ontario, leading to mortality (Gillingwater and Brooks 2002, cited in COSEWIC 2005). Ranavirus was not found in landing’s turtles in Illinois surveys- however, it has been found in other species of turtles (Allender et al. 2009). The disease was documented to cause mortality in Blanding’s turtles in 2012.
Diet: Primarily carnivorous. Possibly omnivorous. Eat crustaceans and other invertebrates, fish, frogs, crayfish, carrion, berries, and vegetable debris (it is possible these were ingested incidentally while eating meat). It is capable of catching live fish.
|Behavior and Locomotion||Becomes dormant under or near water, in mud, or under vegetation or debris. During the nesting season, a female Blanding's turtle may be found more than a kilometer from where it hibernated. Blanding's turtle is a timid turtle and may plunge into water and remain on the bottom for hours when alarmed. If away from water, the turtle will withdraw into its shell. It is very gentle and rarely attempts to bite. It is very agile and a good swimmer.|
|Conservation Status and Efforts||The primary threat to Blanding's turtle is habitat fragmentation and destruction as well as nest predation by unnaturally large populations of predators. It is listed as an endangered species on the IUCN Red List. It is also listed as endangered in Indiana, Illinois, Missouri, Maine, New Hampshire, Massachusetts, and South Dakota and as threatened/endangered throughout Canada, though it has no federal status in the U.S. The Blanding's turtle is also not currently listed under CITES protection, but is under consideration as of 2013. It is considered threatened in New York. Blanding's turtle is also fully protected in Michigan as a special concern species, and is not to be collected or harmed. In Nebraska, this turtle is uncommon in the eastern portion of the state, but common to abundant in the Sand Hills region lakes, ponds, and streams. In Canada, the Great Lakes-St. Lawrence River population in Ontario and Quebec is federally threatened and the Nova Scotia population is endangered. Conservation and recovery efforts in Nova Scotia have been in place for two decades and rely on habitat and life history monitoring based on the work of researchers and volunteers. Habitat protection has proven crucial. The population in Kejimkujik has been placed under the highest level of protection; the McGowan Lake population was initially protected by Bowater but has since been taken over by the Province. In Pleasant River, Nova Scotia Nature Trust protects four separate segments of critical habitat.|
|Distribution||Central and eastern Canada and US. The geographic range centers on the Great Lakes and extends from central Nebraska and Minnesota (where Blanding’s turtle twice failed to become the state reptile) eastward through southern Ontario and the south shore of Lake Erie as far east as northern New York. There are also isolated populations in southeastern New York (Dutchess County), New England and Nova Scotia.|
Family Testudinidae (tortoises)
Family Testudinidae has 15 genera and 45 species.
|Etymology||See #Order Testudines/Chelonia.|
|Physical Appearance||A&P: Pectoral and pelvic girdles are inside rib cage (unique among vertebrates). Almost all have domed shells. Columnar/elephantine feet. Vary in size from a few centimeters to two meters.
Sexual dimorphism: Many species of tortoises are sexually dimorphic, though the differences between males and females vary from species to species. In some species, males have a longer, more protruding neck plate than their female counterparts, while in others, the claws are longer on the females. In most tortoise species, the female tends to be larger than the male. The male plastron is curved inwards to aid reproduction. The easiest way to determine the sex of a tortoise is to look at the tail. The females, as a general rule, have smaller tails, dropped down, whereas the males have much longer tails which are usually pulled up and to the side of the rear shell.
Brain: The brain of a tortoise is extremely small. The tortoises, from Central and South America, do not have an area in the brain called the hippocampus, which relates to emotion, learning, memory and spatial navigation. Studies have shown that red-footed tortoises may rely on an area of the brain called the medial cortex, an area that humans use for actions such as decision making. In the 17th century, Francesco Redi performed an experiment that involved removing the brain of a land tortoise, which then proceeded to live six months. Freshwater tortoises, when subjected to the same experiment, continued similarly, but did not live so long. Redi also cut the head off a tortoise entirely, and it lived for 23 days.
Shell: Most tortoises have a large and dome-shaped shell that makes it difficult for predators to crush the shell between their jaws (one of the few exceptions is the African pancake tortoise, which has a flat, flexible shell that allows it to hide in rock crevices).
|Life Cycle||Lifespan: Galápagos tortoises are noted to live over 150 years, but an Aldabra giant tortoise named Adwaita may have been the longest living at an estimated 255 years. The oldest tortoise ever recorded, and one of the oldest individual animals ever recorded, was Tu'i Malila, which was presented to the Tongan royal family by the British explorer Captain Cook shortly after its birth in 1777. Tu'i Malila remained in the care of the Tongan royal family until its death by natural causes on May 19, 1965, at the age of 188. The record for the longest-lived vertebrate is exceeded only by one other, a koi named Hanako whose death on July 17, 1977, ended a 226-year lifespan. The Alipore Zoological Gardens in India were the home to Adwaita, which zoo officials claimed was the oldest living animal until its death on March 23, 2006. Adwaita (sometimes spelled with two ds) was an Aldabra giant tortoise brought to India by Lord Wellesley, who handed it over to the Alipur Zoological Gardens in 1875 when the zoo was set up. West Bengal officials said records showed Adwaita was at least 150 years old, but other evidence pointed to 250. Adwaita was said to be the pet of Robert Clive. Harriet was a resident at the Australia Zoo in Queensland from 1987 to her death in 2006; she was believed to have been brought to England by Charles Darwin aboard the Beagle and then on to Australia by John Clements Wickham. Harriet died on June 23, 2006, just shy of her 176th birthday. Timothy, a spur-thighed tortoise, lived to be about 165 years old. For 38 years, she was carried as a mascot aboard various ships in Britain's Royal Navy. Then in 1892, at age 53, she retired to the grounds of Powderham Castle in Devon. Up to the time of her death in 2004, she was believed to be the United Kingdom's oldest resident. Jonathan, a Seychelles giant tortoise living on the island of St Helena, may be as old as 182 or 178 years.
Breeding: Female tortoises dig nesting burrows in which they lay from 1 to 30 eggs. Egg-laying typically occurs at night, after which the mother tortoise covers her clutch with sand, soil, and organic material. The eggs are left unattended, and depending on the species, take from 60 to 120 days to incubate (100 days to 18 months?). The size of the egg depends on the size of the mother and can be estimated by examining the width of the cloacal opening. The plastron of a female tortoise often has a noticeable V-shaped notch below the tail which facilitates passing the eggs. Upon completion of the incubation period, a fully formed hatchling uses an egg tooth to break out of its shell. It digs to the surface of the nest and begins a life of survival on its own. They are hatched with an embryonic egg sac which serves as a source of nutrition for the first three to seven days until they have the strength and mobility to find food. Juvenile tortoises often require a different balance of nutrients than adults, so may eat foods which a more mature tortoise would not. For example, the young of a strictly herbivorous species commonly will consume worms or insect larvae for additional protein.
Growth rings: The number of concentric rings on the carapace, much like the cross-section of a tree, can sometimes give a clue to how old the animal is, but, since the growth depends highly on the accessibility of food and water, a tortoise that has access to plenty of forage (or is regularly fed by its owner) with no seasonal variation will have no noticeable rings. Moreover, some tortoises grow more than one ring per season, and in some others, due to wear, some rings are no longer visible.
|Ecology, Habitat and Diet||Habitat: Terrestrial (desert, grassland, scrub)
Diet: Most land-based tortoises are herbivores, feeding on grasses, weeds, leafy greens, flowers, and some fruits, although some omnivorous species are in this family. Pet tortoises typically require diets based on wild grasses, weeds, leafy greens and certain flowers. Certain species consume worms or insects and carrion in their normal habitats. Too much protein is detrimental in herbivorous species, and has been associated with shell deformities and other medical problems. As different tortoise species vary greatly in their nutritional requirements, it is essential to thoroughly research the dietary needs of individual tortoises.
|Behavior and Locomotion||Usually diurnal. Crepuscular depending on ambient temperature. Generally reclusive.
Dormancy: The tortoise starts digging the ground to form its hybernaculum at the first signs of autumn. It digs with its fore-feet in a very slow motion, and prefers swampy grounds where it could bury itself in mud. It starts losing its appetite for food as the temperature drops until it stops eating. During hibernation it stops breathing as well. When the weather warms up suddenly it stops its digging, and starts it again as soon as the temperature drops. It wakes up from hibernation in the spring, but it does not start eating immediately. Gradually it gains its appetite and energy as the temperature warms up. During hot summer days, tortoises eat voraciously, and spend many hours sleeping. They start sleeping in late afternoon until late the next morning. Although tortoises love warm weather, they avoid hot sun, hiding under green leaves or between vegetation.
Locomotion: Giant tortoises move very slowly on dry land (0.17 mph or 0.27 km/h). The fastest recorded tortoise speed is 5 mph (8.0 km/h).
|Conservation Status and Efforts||According to the IUCN, one species is Critically Endangered or facing an extremely high risk of extinction in the wild, seven are Endangered or facing a very high risk of extinction in the wild, and sixteen are Vulnerable or facing a high risk of extinction in the wild. The U.S. Fish and Wildlife Service lists two U.S. species as Threatened or likely to become endangered in the near future and five foreign species as Endangered, or in danger of extinction throughout all or a significant portion of their range. Although most countries make collecting illegal, it still continues. People find these land-living turtles easy to find and collect.|
|Distribution||Southern North America to southern South America, circum-Mediterranean Euroafrica to Indomalaysia, sub-Saharan Africa, Madagascar, and some oceanic islands.|
|Miscellaneous Information||Symbolize longevity in some cultures such as the Chinese. In Hinduism, Kurma (Sanskrit: कुर्म) was the second Avatar of Vishnu. Like the Matsya Avatara, Kurma also belongs to the Satya Yuga. Vishnu took the form of a half-man, half-tortoise, the lower half being a tortoise. He is normally shown as having four arms. He sat on the bottom of the ocean after the Great Flood. A mountain was placed on his back by the other gods so they could churn the sea and find the ancient treasures of the Vedic peoples. Tortoise shells were used by ancient Chinese (Shang dynasty) as oracle bones to make predictions. The tortoise is a symbol of the Ancient Greek god, Hermes.|
Family Cheloniidae (sea turtles)
Family Cheloniidae comprises six species in five genera (the green/black (sea)/Pacific green turtle Chelonia mydas, the loggerhead sea turtle Caretta caretta, the olive ridley/Pacific ridley sea turtle Lepidochelys olivacea, Kemp's ridley/the Atlantic ridley sea turtle L. kempii, the hawksbill sea turtle Eretmochelys imbricata, and the Australian flatback sea turtle Natator depressus).
|Etymology||The fat of the green turtle is green.|
|Physical Appearance||The only unifying skeletal feature is the platycoelous (one surface flat and one concave) articulation between the sixth and seventh cervical vertebrae. The smallest species is L. kempii (75 cm and 50 kg). The largest species is C. caretta (213 cm).
Shell: Most aquatic turtles have flat, streamlined, wide, and rounded shells which aid in swimming and diving. Incompletely retractile or nonretractile head. Considerably reduced plastron that is connected to carapace by ligaments without a hinge separating the pectoral and abdominal plates of plastron. Oval or heart-shaped. Horny scutes (variable in number, commonly include five vertebrals and six pairs of plastral scutes and usually both an intergular and an interanal scute). Plastron often with persistent fontanelles (one in middle and others in entoplastral and xiphiplastral regions). Hyoplastra and hypoplastra not suturally connected mesially (in the middle) but each with a series of coarse spikes that interdigitate (interlock like fingers of hands put together) mesially. Plastron not cruciform. Posterior plastral lobe relatively long and wide.
Skull: Extensively roofed. Well-developed rhamphothecae (thin horny sheaths of keratin that cover the beaks). Secondary palate.
Limbs: Almost paddle-like flippers for forelimbs. Only turtles where front limbs are stronger than back limbs. Limbs cannot support body weight on land. Webbed hind limbs for steering. Covered with numerous small scales. Highly elongate digits firmly bound together by connective tissue. One or two claws on each limb. Radius and ulna cannot move independently because of juxtaposed rugose (wrinkled) surfaces.
|Life Cycle||Reproductive behaviors among the different species of sea turtles are similar, with slight differences in each of the species. The females come to shore and bury their clutch of eggs on beaches or sandy environments typically at night and well away from the high tide line of the shore. Most females nest only once every three to four years and most species have two to four egg laying time periods per nesting season, which is from spring to late fall. A common number of eggs laid in a nest is often about 100 eggs per clutch. The incubation period of some turtles can range anywhere from 50 to 60 days. The development of the eggs is dependent on the temperature of the environment that they were buried in, with warmer climates bringing about an earlier emergence by the hatchlings. The timing of sea turtle hatching tends to be almost synchronous among the whole clutch of eggs, with just about all the eggs in the nest hatching within the same time. This is thought to aid the process of the hatchlings unburying themselves from the sand and most often occurs at night time. Interestingly enough, temperature has also been linked to the likeliness of hatching's sex, warmer temperature more likely to produce females and colder temperatures more commonly producing males. Courtship and mating usually occur in shallow offshore waters. Mating often involves the male and female pair floating near the surface, with the male's carapace protruding from the water. Females reproduce on multi-year cycles, but produce multiple clutches within a single season. Nesting occurs at night (except in Lepidochelys), and a range of seven to 238 eggs (averages vary across species) are deposited in a single clutch. Require 25 years for sexual maturity.|
|Ecology, Habitat and Diet||Habitat: The habitat range of sea turtles, in general, is known to be far reaching into warmer temperatures and the tropical and subtropical areas of the Pacific and Atlantic Oceans and is even also found in warmer seas such as the Mediterranean Sea. Within these temperamental biomes, sea turtles frequent nearby the coastlines when nesting, and spend most of their lives swimming out in waters over the continental shelf when feeding. Travelling throughout the oceans has been reported in Olive Ridleys Sea Turtles but more often than not, they tend to frequent bays and estuaries. Marine.
Predators: Adult turtles have relatively few natural predators, although sharks and saltwater crocodiles are known to consume adults, and nesting females are preyed upon by coyotes and other canids. Eggs and hatchlings are the most vulnerable, falling prey to insects, crustaceans, mollusks, small mammals, birds, other reptiles, and various fishes.
Diet: The diets of all the sea turtle species, except for the green turtle, which is only carnivorous from hatchling to juvenile, are mostly carnivorous, with some herbivorous tendencies. Turtles feed mainly on sea sponges, jellyfish, mollusks and barnacles, sea urchins, and even fish. The green sea turtle, on the other hand, feeds primarily on many different types of sea grasses. Sea turtles are omnivorous and feed on a variety of sponges, cnidarians, mollusks, crustaceans, algae, plants, and fish.
|Conservation Status and Efforts||The conservation status of each of the seven turtle species are mostly all endangered or threatened. The green and loggerhead sea turtles are categorized as endangered, olive ridleys are classified as vulnerable, Kemp’s ridleys, and hawksbills sea turtles are critically endangered and the flatback sea turtle does not have enough data to draw an accurate conclusion on conservation status. This is due to their slow growth rate to full maturity. Many do not ever make it to full adulthood because of being caught, either intentionally or by accident by big fisheries and fishermen. Their slow maturity rate, which most of the time means about 10 or 15 years, does not allow the turtles to fully reproductively mature to have hatchlings of their own. International legislation has been put into place to attempt to reduce the number of sea turtle deaths but this does not deter the demand for the consumption of turtle eggs around the world, and some are hunted for their shells. In addition to this, turtles face another threat which has been theorized as being linked to human pollution. A growing number of turtles have been found with fibrous tumor-like growths on their skin, mouths, and even internal organs with no clear cause having been found to be the cause of this disease, and in some areas the number of infected turtles reaching over 70%. It is unknown what the effects of the growths will have in the long term for sea turtle populations. Sea turtles play a very important part in marine ecosystems. They maintain the balance of health of sea grasses and reefs, which in turn benefit the likes of shrimp, lobsters, and tunas. They are also the last living members of the seafaring category of marine reptiles that have been in existence on Earth for at least the past 100 million years. Additionally, they are also highly significant to multiple cultures and are also popular touristic animals, which give them lots of value to their conservation.|
|Distribution||Temperate and tropical regions of the Atlantic, Pacific, and Indian Oceans. Typically found from North Carolina to Florida but ranges from Newfoundland to Argentina. Primarily nest in the Atlantic and Indian Oceans. Most records of loggerheads in the Pacific are sightings of juveniles off the coasts of California and Mexico. Also records in Mediterranean Sea. Some populations remain primarily in the coastal continental shelf regions near their nesting sites while other populations are known to migrate across deep waters. Ranges from sea level (where sea turtles lay their eggs) to pelagic ocean (where adults spend majority of their time). Less is known about where young and juvenile turtles spend their lives but it is believed that the young take refuge in nearshore coastal areas and that once they reach the open oceans juveniles still live primarily in the upper fifteen feet (five meters) of the water column.|
|Miscellaneous Information||A group of sea turtles is a bale. The fossil record for Cheloniids places them among the oldest turtles. Six extinct genera, as well as the extant genera Caretta and Chelonia, date from the Upper Cretaceous of Europe and North America. The leatherback sea turtle (Dermochelys coricea) is not part of Cheloniidae but in Dermochelyidae.|
Family Trionychidae (soft shelled turtles)
Trionychidae consists of the subfamilies Cyclanorbinae and Trionychinae. Many species were traditionally in Trionyx but have since been moved.
|Alternate names||Pancake turtles|
|Etymology||"Softshell" - Carapaces lack horny scutes; "Trichonyidae" - three claws.|
|Physical Appearance||Shell: Carapaces lack horny scutes (though the spiny softshell, Apalone spinifera, does have some scale-like projections, hence its name). Carapace is leathery and pliable particularly at the sides. Central part of carapace has a layer of solid bone beneath it as in other turtles (but this is absent at the outer edges). Some species also have dermal bones in the plastron but these are not attached to the bones of the shell. Lattice-like plastron (either fused or separate).
Adaptations: Light and flexible shell of these turtles allows them to move more easily in open water and muddy lake bottoms. Having a soft shell also allows them to move much faster on land than most turtles. Their feet are webbed and are three-clawed. The carapace color of each type of softshell turtle tends to match the sand and/or mud color of its geographical region, assisting in their "lie and wait" feeding methodology. Many must be submerged in order to swallow their food. They have elongated, soft, snorkel-like nostrils. Their necks are disproportionately long in comparison to their body sizes, enabling them to breathe surface air while their bodies remain submerged in the substrate (mud or sand) a foot or more below the surface. Softshells are able to "breathe" underwater with rhythmic movements of their mouth cavity that contains numerous processes that are copiously supplied with blood, acting similarly as gill filaments in fish. Cutaneous (relating to the skin) respiration. This enables them to stay underwater for prolonged periods. Moreover, the Chinese softshell turtle has been shown to excrete urea while "breathing" underwater; this is an efficient solution when the animal does not have access to fresh water, e.g., in brackish-water environments. Forelimbs substantially modified into swimming paddles.
Sexual dimorphism: Females can grow up to several feet in carapace diameter while males stay much smaller.
Size: Pelochelys cantorii (found in southeastern Asia) is the largest softshell turtle (70-100 cm and can grow to over 100 kg).
Mandibles: According to Ditmars (1910): "The mandibles of many species form the outer border of powerful crushing processes—the alveolar surfaces of the jaws", which aids the ingestion of tough prey such as molluscs. These jaws make large turtles dangerous, as they are capable of amputating a person's finger, or possibly their hand.
|Life Cycle||Courtship has been observed in a few species and involves acts such as head bobbing between a pair in some and the male rubbing the carapace of the female with his head in others. Overall, however, knowledge of reproductive behavior is poor. Females reproduce annually, and nests contain around 20 eggs. More than one clutch per season is often produced.|
|Ecology, Habitat and Diet||Habitat: Include slow moving streams, swift rivers, lakes, ponds, and even brackish waters, but a soft bottom is requisite.
Diet: Most are strict carnivores, with diets consisting mainly of fish, aquatic crustaceans, snails, amphibians, and sometimes birds and small mammals. Opportunistic.
|Behavior and Locomotion||Spend much time buried in the mud, and basking is not common.|
|Conservation Status and Efforts||According to the IUCN, more than half of the family's 25 species are at risk. Five species are Critically Endangered, which means that they are facing an extremely high risk of extinction in the wild. In addition, five are Endangered and face a very high risk of extinction in the wild, and six are Vulnerable and at high risk of extinction in the wild. The U.S. Fish and Wildlife Service also lists four non-U.S. species as Endangered, or in danger of extinction throughout all or a significant portion of their range. Softshells are coping with overhunting, polluted waters that can weaken and/or kill the animals, and loss of their habitat.
As food: Softshell turtles are eaten as a delicacy in most parts of their range, particularly in East Asia. A Chinese dish stews them with chicken. According to a 1930 report by Soame Jenyns, Guangdong restaurants had them imported from Guangxi in large numbers; "eaten stewed with almonds, roast with chili sauce or fried with bamboo shoots, they [were] considered a great delicacy." World-wide, the most commonly consumed softshell species is the Chinese softshell Pelodiscus sinensis. As noted Japanese biologist Kakichi Mitsukuri pointed out in 1904, the Japanese variety of this turtle, which at time was classified as Trionyx japonicus, occupied a place in Japanese cuisine as esteemed as the diamondback terrapin in the United States or the green turtle in England. The farming of this "luscious reptile", known in Japan as suppon, was already developed on an industrial scale in that country by the late 19th century. Due to rising demand and overhunting, the price of Pelodiscus sinensis in China skyrocketed by the mid-1990s; large-scale turtle farming in China and neighboring countries; raising this species by hundreds of millions was the response, with prices soon returning to a more affordable level. Another species, Palea steindachneri, is farmed in China, as well, but on a much smaller scale (with farm herds measured in hundreds of thousands, rather than hundreds of millions). In the United States, harvesting softshells (e.g. Apalone ferox) was, until recently, legal in Florida. Environmental groups have been advocating the authorities' banning or restricting the practice. The Florida Fish and Wildlife Conservation Commission responded by introducing the daily limit of 20 turtles for licensed harvesters—a level which the turtle advocates consider unsustainable, as there may be between 100 and 500 hunters statewide. While some catch was consumed locally, most was exported; the Commission estimated (2008) around 3,000 pounds of softshell turtles were exported each week via Tampa International Airport. New rules, in effect as of July 20, 2009, restrict collecting any wild turtles to one turtle per person per day, completely prohibit collection of softshells (Apalone) in May through July, and prohibit trade in turtles caught from the wild. An exemption is provided for licensed turtle farms that need to catch turtles in the wild to serve as their breeding stock. Some other US states, too, have already adopted strict limitations on wild turtle trade. In 2009, South Carolina passed the law (Bill H.3121) restricting interstate and international export of wild-caught turtles (both soft-shell and some other species) to 10 turtles per person at one time, or 20 turtles per person per year.
|Distribution||Eastern North America, Africa, Asia, and the Indo-Australian archipelago.|
|Miscellaneous Information||Appeared early in fossil record (first appeared in North America and Europe in the Late Cretaceous, or 100.5-66 mya, and Paleocene, 66-55 mya, respectively).|