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Home -> Kingdom Animalia -> Phylum Chordata -> Subphylum Vertebrata -> Class Reptilia -> Order Testudines -> Family Emydidae -> Species Deirochelys reticularia

Deirochelys reticularia
chicken turtle



2010/02/07 02:32:52.046 US/Eastern

By Tanya Dewey

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Testudines
Family: Emydidae
Genus: Deirochelys
Species: Deirochelys reticularia

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. (Ernst, Lovich, and Barbour, 1994)

Biogeographic Regions:
nearctic (native ).

Habitat

Depth
0.01 to > 2 m
(0.03 to ft)


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. (Ernst, Lovich, and Barbour, 1994; Gibbons and Greene, 1978)

These animals are found in the following types of habitat:
temperate ; terrestrial ; freshwater .

Terrestrial Biomes:
forest .

Aquatic Biomes:
lakes and ponds; rivers and streams; temporary pools.

Wetlands: marsh , swamp , bog .

Other:
riparian .

Physical Description

Length
15.30 to 25.40 cm
(6.02 to 10 in)


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. ("Chicken Turtle", 2005; Ernst, Lovich, and Barbour, 1994; Gibbons and Greene, 1978)

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. (Ernst, Lovich, and Barbour, 1994; Gibbons and Greene, 1978)

Some key 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. (Ernst, Lovich, and Barbour, 1994)

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. (Gibbons and Greene, 1978)

Special features of growth:
temperature sex determination.

Reproduction

Breeding interval
Chicken turtles lay up to two clutches each year.

Breeding season
Breeding occurs two times a year in the northern part of their range and throughout the year in the southern part of their range.

Number of offspring
2 to 19; avg. 8.50

Gestation period
78 to 152 days

Age at sexual or reproductive maturity (female)
5 years (average)

Age at sexual or reproductive maturity (male)
2 to 3 years

Males court female chicken turtles by vibrating their foreclaws against the female's face. Once the female is receptive, copulation occurs. (Ernst, Lovich, and Barbour, 1994)

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. (Buhlmann and Gibbons, 1995; Congdon, Gibbons, and Greene, 1983; Ernst, Lovich, and Barbour, 1994; Gibbons and Greene, 1978; Gibbons, 2004)

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. (Buhlmann and Gibbons, 1995; Congdon, Gibbons, and Greene, 1983; Ernst, Lovich, and Barbour, 1994)

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. (Ernst, Lovich, and Barbour, 1994)

Parental investment:
pre-fertilization (provisioning, protecting: female).

Lifespan/Longevity

Extreme lifespan (wild)
24 years (high)

Typical lifespan (wild)


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. (Ernst, Lovich, and Barbour, 1994; Gibbons and Greene, 1978; Thomas et al., 1997)

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. (Ernst, Lovich, and Barbour, 1994)

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. (Ernst, Lovich, and Barbour, 1994)

Key behaviors:
natatorial ; diurnal ; motile ; sedentary ; hibernation ; aestivation; solitary .

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.

Communicates with:
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. ("Chicken Turtle", 2005; Buhlmann and Demuth, 1997)

Primary Diet:
omnivore .

Animal Foods:
amphibians; fish; insects; aquatic crustaceans.

Plant Foods:
leaves.

Predation

Known predators

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). (Buhlmann and Mitchell, 2003; Buhlmann, 1995; Ernst, Lovich, and Barbour, 1994)

Ecosystem Roles

Chicken turtles are both predators and prey. They impact populations of aquatic insects, crustaceans, tadpoles, and aquatic vegetation. (Buhlmann, 1995)

Economic Importance for Humans: Negative

There are no negative impacts of chicken turtles on humans. (Buhlmann and Mitchell, 2003; Peacock, 2000)

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. (Ernst, Lovich, and Barbour, 1994)

Ways that people benefit from these animals:
food .

Conservation Status

IUCN Red List: [link]:
Not Evaluated.

US Federal List: [link]:
No special status.

CITES: [link]:
No special status.

State of Michigan List: [link]:
No special 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. (Buhlmann and Mitchell, 2003)

Other Comments

Chicken turtle fossils are known from the Pliocene, Pleistocene, and recent sites in Florida. (Ernst, Lovich, and Barbour, 1994)

For More Information

Find Deirochelys reticularia information at

Contributors

Tanya Dewey (author), Animal Diversity Web, University of Michigan Museum of Zoology.

References

2005. Chicken Turtle. Pp. 199 in The New Encyclopedia Britannica, Vol. 3, 15th Edition. Chicago: Encyclopedia Britannica, Inc..

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., 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.

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.

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.

2010/02/07 02:32:53.809 US/Eastern

To cite this page: Dewey, T. 2006. "Deirochelys reticularia" (On-line), Animal Diversity Web. Accessed February 09, 2010 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Deirochelys_reticularia.html.

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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