Natural History Information
Range and Habitat
- Diamondback terrapins occur along the Atlantic and Gulf coasts from Cape Cod to Texas, and also the Florida Keys. They live in brackish (half salt/half fresh) water, coastal marshes, tidal flats, coves, estuaries, and lagoons behind barrier beaches.
- Average lifespan for this species is 20 to 25 years.
- They are important for population control of prey species.
- Life Cycle Natural History Relevant Information
- These turtles spend most of their time in the water, only coming onto land to bask or lay eggs. In the wild, these wary turtles are quick to flee and difficult to observe. In captivity, the diamondback terrapin are known to recognize habits, and learn quickly what times people are normally around. They seem very sociable except when their cage is too small. They enjoy basking together, often one on top of another.
- Diamondback terrapins hibernate during the winter months. Some will bury themselves in the mud along the creek banks and others simply sink to the bottom of marsh creeks and become inactive. The terrapins become active again as the waters warm up in the spring.
- Temperature, Humidity, Light Cycles
- Social Housing/Colony Management
- This is not a social species.
- Other General Housing Requirements or Management information
- Life Cycle Relevant Information
- In the wild, terrapins are at the top of the salt marsh food web, just under osprey. This species feeds largely on fish, crustaceans, mollusks, and insects. Diamondback terrapins are especially fond of crayfish, clams, and snails.
- Diet under human care
- In captivity, they are fed pelleted turtle food, earthworms, and smelt
- Behavioral Relevant Information
- Environmental Enrichment
- Behavioral Enrichment
- Other Enrichment Resources
- Check out the Reptelligence Facebook page and Reptelligence website for enrichment and training inspiration.
- Advancing Herpetological Husbandry July 2018 Quarterly Newsletter- Environmental Enrichment for Reptiles By Charlotte James
- Behaviors Trained
- Reinforcers used & schedule of reinforcement
- Threats and Conservation Status
- Smaller individuals are more at risk of predation by raccoons, skunks, rats, crows, and seagulls.
- The over-harvesting of these turtles for food led to a major decline in terrapin numbers. From the 1700s through the early 1900s, diamondback terrapins were considered a delicacy. Terrapin soup was served in many of the finer restaurants on the east coast. this led to a serious decline in their numbers and they were even thought to be extinct in some regions. Once terrapins were no longer harvested, many populations had opportunities to recover. Hatch and release programs, along with conservation groups are a major reason why diamondback terrapins are finally beginning to rise in numbers again.
- Terrapin hunting is still legal in some states, although a license is required and the industry is regulated. A bigger problem for this species is cars. Many females are hit by cars when they are making their way across roads to lay their eggs. Diamondback terrapins also drown in crab pots and are killed or injured by boat propellers.
- Diamondback terrapins are classified as threatened by CITES.
- Habitat loss due to humans
- In general, animals seen at the zoo do not make good pets. Most have specialized dietary, veterinary, housing, and social needs that are difficult or impossible for even dedicated pet owners to meet. Always ensure that your future pet has not been taken from the wild. Captured animals are typically mistreated by profit-motivated traffickers and dealers, resulting in many animal deaths; well-meaning animal lovers may feel like they are rescuing animals by purchasing them but are really perpetuating the cruelty. In addition, many exotic pets are released by their owners when they become too dangerous or demanding, often with devastating effects on local ecosystems. Animals that should never be kept as pets include all bats, primates, and exotic carnivores. Birds, fish, and reptiles have specialized needs, are frequently wild-caught, and damage the local environment if released; guests should be advised to educate themselves and proceed with caution. Domestic dogs and cats are almost always the best option! Many deserving animals are available for adoption at animal shelters.
- Interesting Natural History Information
- This is a small-to-medium sized turtle with markings and concentric grooves and ridges on each large scute (the scales on the shell.) The limbs and head are flecked or spotted. There is considerable variation in appearance. The carapace (the top of the shell) is gray, light brown, or black. If the shell is lighter, the scutes are ringed concentrically with darker pigment. The oblong, plastron (bottom of the shell) is usually greenish to yellow with dark blotches or flecks. The short head is narrow in males and broad in females. The snout does not protrude, and the upper jaw is either un-notched or slightly notched, so it sometimes looks as if they are smiling. The head and neck are gray with flecks or curved markings. Eyes are black, large, and prominent.
- Mature female diamondbacks are almost twice the size of mature males, with females having disproportionately larger heads. Males grow to be 4 to 5.5 inches long, and females grow to 6 to 9 inches long.
- Females reach sexual maturity at about 6 years of age, while males are mature at 3 years. Courtship and mating occur from late March to May, during the daylight hours. Nesting extends from April through July, depending on the latitude. Nests are located above the high-tide mark along the sandy edges of salt marshes and river, in dunes of sandy beaches, and on offshore lines. Nests are flask-shaped to triangular, and 4 to 8 inches deep.
- At least two clutches can be laid each season, and females are also able to store viable sperm for several years. Clutch size varies from 4 to 18 eggs. Average incubation period is 65 to 80 days, depending on the depth of the nest and the ambient temperature. When they hatch, baby terrapins are only about 1 inch long.
- Did you know…
- Terrapins are the only turtle in the world to have adapted to brackish water ranging from ocean conditions to almost fresh water habitats.
- It is not known how long terrapins can hold their breath. It has been documented that sea turtles can hold their breath for 5 hours, although they usually only stay underwater for 10 minutes at a time
Handling & Presentation Tips
Public Contact and Interaction Guidelines
- Maryland Zoo in Baltimore: Tricky to hold for programming.
- Brandywine Zoo: During cool weather (under 65°F), supplemental heat is provided with a hot water bottle set to one side of the cooler. Wrap bottle with newspaper for lizards or snakes traveling with the bottle loose, to make cleanups easier in the case of defecation while traveling.
- Brandywine Zoo: aquatic turtles travel in a locking-lid type tote that have been amended with extra ventilation holes on the lid (with a wood-burning tool). Some species are transported with 1-2cm of water, while others are transported with the tote lined with very wet (but no standing water) paper towels.
- Brandywine Zoo: During cool weather, the tote is transported inside a larger, secondary Coleman style cooler.
- After looking at other AZA institutions for surplus animals, check with your local herpetological society and reptile rescue organizations. Many of these animals are purchased by the public at reptile stores and expos and owners are unable to keep them for their whole lifespan. If purchasing, look for a reputable breeder to avoid wild caught specimens.
- Check out sample animal policies, handling sheets, and fact sheets on our Example Policies & Guidelines page
- View past issues of Program Animal SAG Newsletters
- Ambassador Animal SAG Newsletter Vol. 2, Issue 3: Temperature and Transport: Welfare Implications for Ambassador Ectotherms
- Choice, Control, and Training in Ectotherms, By Carrie Kish
- Stress Management in Reptiles and Frogs
- Check out the Advancing Herpetological Husbandry Facebook group. They have also published several newsletters (see Reptiles page for links).
Contributors and Citations
- The Philadelphia Zoo
- Houston Zoo, Natural Encounters
- Cover photo: By Ltshears (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons
Comments from the Rating System
- Maryland Zoo in Baltimore: Requires aquatic space, great educational content.