Geographic Range
Chicken turtles, made up of three subspecies, are found in suitable habitat throughout
the southeastern United States.
Deirochelys reticularia
is found in coastal areas from Virginia to Texas and northward into Oklahoma and
Arkansas. The Florida subspecies,
D. r. chrysea
, is limited to peninsular Florida. The eastern,
D. r. reticularia
, and western,
D. r. miaria
, subspecies of chicken turtles are separated by the Mississippi River.
Habitat
Chicken turtles are semi-aquatic basking turtles, found on both water and land. They
prefer quiet bodies of water: ponds, lakes, ditches, marshes, cypress swamps and Carolina
bays. They bask on logs, rocks, and other emergent structures. They prefer water with
plenty of aquatic vegetation and a soft substrate. Chicken turtles are tolerant of
ephemeral aquatic habitats and readily travel onto land to burrow into the soil and
escape dry conditions. They have been found at water depths of a few centimeters to
more than 2 m.
- Habitat Regions
- temperate
- terrestrial
- freshwater
- Terrestrial Biomes
- forest
- Aquatic Biomes
- lakes and ponds
- rivers and streams
- temporary pools
- Other Habitat Features
- riparian
Physical Description
Chicken turtles are readily identified by their long, striped necks. Head and neck
length is approximately equal to their plastron length, or up to 80% of the length
of their carapace. They are sometimes called “American snake necks” because of this.
They are small to medium-sized turtles with a pear-shaped, olive to dark brown carapace
marked with a reticulate pattern of yellow to orange lines. They grow up to 25.4 cm
long. The plastron is solid yellow and they have yellow stripes on their legs. Females
are typically 1.5 times larger than males. Males have thicker tails, longer front
claws, and more compressed shells than do females.
Gibbons and Greene (1978) described patterns of growth in chicken turtles. Younger
chicken turtles grow proportionally faster than adults but age at maximum size is
not known. Young are 2.5 cm in diameter at hatching. Males mature at 10.2 cm, while
females are mature at 17.8 cm. Chicken turtles may grow to a maximum size of 25.4
cm, though the typical adult ranges from 15.3 to 17.8 cm.
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
- sexes shaped differently
Development
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 degrees Celsius in South Carolina and in 78 to 89 days at
25 to 29 degrees Celsius in Florida. Some eggs may overwinter in the nest before hatching.
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% becoming males at incubation temperatures of 30 degrees
Celsius.
Although size and age are directly related in chicken turtles, some individuals may
experience several years of little or no growth, depending on environmental conditions.
- Development - Life Cycle
- temperature sex determination
Reproduction
Males court female chicken turtles by vibrating their foreclaws against the female's
face. Once the female is receptive, copulation occurs.
- Mating System
- polygynandrous (promiscuous)
Chicken turtles are different from most other North American turtles because they
nest in either the fall and 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). The highest percentages of nesting females in South Carolina were during
the months of March and September. Florida chicken turtles nest nearly continuously
from mid-September to early March. Females excavate cylindrical nests on land in a
variety of soil types, from sandy to heavy soils. Females lay 2 clutches each year
in South Carolina, with 5 to 15 elliptical eggs per clutch (average of 8); in Florida
clutch size is 2 to 19 (average 9). The eggs are flexible and oblong, measuring 28
to 40 mm long and weighing 8.7 to 13.3 g. Eggs laid in the fall are usually larger
than those laid in spring.
Male chicken turtles reach sexual maturity at 7.5 to 8.5 cm in carapace length, usually
during their second or third year. Females mature at carapace lengths of 14.1 to 16
cm, after about 5 years of growth.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- oviparous
Like most turtles, chicken turtles do not care for the hatchlings. Parents do not
help the young once the eggs are laid.
- Parental Investment
-
pre-fertilization
- provisioning
-
protecting
- female
Lifespan/Longevity
Wild chicken turtles in South Carolina have been recaptured up to 15 years after their
first capture. Some reached maximum ages of 20 to 24 years.
Behavior
Chicken turtles are regularly encountered on land, either migrating between aquatic
habitats or seeking areas to burrow into the soil and escape dry conditions. Males
generally move farther than females. In South Carolina activity on land is highest
in March and April. Chicken turtles spend much of their time basking and active turtles
have been recorded with cloacal temperatures of 25.5 to 25.6 degrees Celsius. Chicken
turtles hibernate in the soft mud and vegetation of bodies of water in the northern
parts of their range. Florida chicken turtles remain active throughout the year. They
are active during the day.
- Key Behaviors
- natatorial
- diurnal
- motile
- sedentary
- hibernation
- aestivation
- solitary
Home Range
A single, marked chicken turtle moved 612 meters in a period of 8 months. Otherwise,
there is little information on home ranges in chicken turtles, some researchers have
suggested that movement is random or directional.
Communication and Perception
Males use tactile communication to make females receptive to copulation. As in most turtles, chicken turtles use vision, touch, and chemical cues to perceive their environment. They are wary when basking.
- Communication Channels
- tactile
- Perception Channels
- visual
- tactile
- vibrations
- chemical
Food Habits
Chicken turtles are omnivorous, though they are somewhat more carnivorous than other
turtle species. During their first year of life they may be almost completely carnivorous.
Chicken turtles in South Carolina were found to be completely carnivorous during June
and July (Buhlmann and Demuth, 1997). They eat primarily crustaceans, aquatic insects,
tadpoles, fish, and plants. Chicken turtles use their well-developed hyoid apparatus
to create suction that pulls food items into their throats.
- Primary Diet
- omnivore
- Animal Foods
- amphibians
- fish
- insects
- aquatic crustaceans
- Plant Foods
- leaves
Predation
Eastern moles (
Scalopus aquaticus
) are a significant predator of chicken turtle nests (Allen et al., 2005). Raccoons
(
Procyon lotor
) and snapping turtles (
Chelydra serpentina
) are potential predators (Buhlmann, 1995).
Ecosystem Roles
Chicken turtles are both predators and prey. They impact populations of aquatic insects,
crustaceans, tadpoles, and aquatic vegetation.
Economic Importance for Humans: Positive
Chicken turtles were once found in the food markets of the southern United States
for their meat. Their common name, "chicken" turtle, refers to their taste.
- Positive Impacts
- food
Economic Importance for Humans: Negative
Conservation Status
Chicken turtle populations are currently considered stable throughout their range,
although they do face potential threats. Habitat destruction reduces suitable habitat
for foraging, migration, and hibernation. Chicken turtles are sometimes killed on
roads as they migrate between habitats. Hunting for food also impacts populations
of chicken turtles.
Other Comments
Chicken turtle fossils are known from the Pliocene, Pleistocene, and recent sites
in Florida.
Additional Links
Contributors
Tanya Dewey (author), Animal Diversity Web.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- terrestrial
-
Living on the ground.
- freshwater
-
mainly lives in water that is not salty.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- marsh
-
marshes are wetland areas often dominated by grasses and reeds.
- swamp
-
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
- bog
-
a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.
- riparian
-
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- heterothermic
-
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- natatorial
-
specialized for swimming
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- hibernation
-
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
- solitary
-
lives alone
- tactile
-
uses touch to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- vibrations
-
movements of a hard surface that are produced by animals as signals to others
- chemical
-
uses smells or other chemicals to communicate
- food
-
A substance that provides both nutrients and energy to a living thing.
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
References
Buhlmann, K., J. Demuth. 1997. Diet of the Turtle Deirochelys reticularia on the Savannah River Site, South Carolina. Journal of Herpetology , Volume 31 No. 3: 450-453.
Buhlmann, K., J. Gibbons. 1995. "University of Georgia Savannah River Ecology Laboratory News Release" (On-line). Unusual turtle species serving as a model in conservation of wetlands. Accessed March 15, 2006 at http://www.uga.edu/srel/chicken.htm .
Buhlmann, K. 1995. Habitat Use, Terrestrial Movements, and Conservation of the Turtle, Deirochelys reticularia in Virginia. Journal of Herpetology , Volume 29 Number 2: 173-181.
Buhlmann, K., J. Mitchell. 2003. "Virginia Cooperative Extension" (On-line). Sustaining America's Aquatic Biodiversity. Accessed March 05, 2006 at http://www.ext.vt.edu/pubs/fisheries/420-529/420-529.html#L5 .
Cervone, S., V. Ramey. 2004. "Plant Management in Florida Waters" (On-line). Florida's Freshwater Turtles. Accessed March 04, 2006 at http://aquat1.ifas.ufl.edu/guide/turtles.html .
Congdon, J., J. Gibbons, J. Greene. 1983. Parental Investment in the Chicken Turtle (Deirochelys reticularia). Ecology , Volume 64 No. 3: 419-425.
Ernst, C., J. Lovich, R. Barbour. 1994. Turtles of the United States and Canada . Washington, D.C.: Smithsonian Institution Press.
Gibbons, J., J. Greene. 1978. Selected Aspects of the Ecology of Chicken Turtle, Deirochelys reticularia (Latreille) (Reptilia, Testudines, Emydidae). Journal of Herpetology , Volume 12 Number 2: pg. 237-241.
Gibbons, J. 1969. Ecology and Population Dynamics of the Chicken Turtle, Deirochelys reticularia. Copeia , Volume 1969 No. 4: 669-676.
Gibbons, J. 2004. "University of Georgia Savannah River Ecology Laboratory" (On-line). Why Did the Turtle Cross the Road?. Accessed March 15, 2006 at http://www.uga.edu/srelherp/ecoview/Eco12.htm .
Peacock, T. 2000. Deirochelys reticularia (chicken turtle). Herpetological Review , 31/2: 110-111.
Thomas, R., D. Beckman, K. Thompson, K. Buhlmann, J. Gibbons, D. Moll. 1997. Estimation of Age for Trachemys scripta and Deirochelys reticularia by Counting Anuual Growth Layers in Claws. Copeia , Volume 1997 No. 4: pp. 842-845.
2005. Chicken Turtle. Pp. 199 in The New Encyclopedia Britannica , Vol. 3, 15th Edition. Chicago: Encyclopedia Britannica, Inc..