DIAMONDBACK TERRAPINS 



Habits & 



By Kathy Hart 



In salt marshes from Cape Cod to 

 Texas lives a reptile of distinction. 



At the turn of the century, the 

 diamondback terrapin was the catch of 

 the day in the culinary world. Its meat 

 was lavishly prepared into a soup that 

 graced the tables of America's 

 nouveau riche. In fact, turtle soup 

 became so popular that wild popula- 

 tions of this heralded terrapin dropped 

 dangerously low and prices for the 

 reptilian harvest skyrocketed to $125 a 

 dozen by 1920. 



The government even established 

 a hatchery, which was located on 

 Pivers Island near Beaufort. Opened in 

 1913, the hatchery released more than 

 a quarter of a million young turtles 

 into the salt marshes along the East 

 Coast before it closed in the late 

 1930s. But no one knows how well the 

 farm-raised hatchlings survived after 

 release. 



Populations did rebound. It's more 

 likely, however, that a combination of 

 events — the Depression, World War 

 II and the terrapin's own high cost and 

 scarcity — led to its disappearance 

 from the dinner table and a renewed 

 chance for survival in the estuary. 



In North Carolina, the diamond- 

 back terrapin has been designated a 

 species of special concern by the N.C. 

 Wildlife Resources Commission. But 

 no regulations restrict its harvest. 



The reptiles are not uncommon in 

 Tar Heel estuaries. Often they are 

 heard rather than seen as they paddle 

 among the salt marsh grasses. The 

 terrapin's powerful jaws pop as they 

 snap down on their favorite meal — 

 periwinkle snails. 



Female diamondback terrapins 

 reach a maximum length of about 9 

 inches. Males are smaller, seldom 

 more than 5 inches long. Females 

 also have distinctively larger and 

 flatter heads, deeper shells and 

 shorter tails than males. Some 

 diamondbacks are distinguished by a 

 debonair mustachelike marking on 

 the upper jaw. 



The terrapin's upper shell may 

 be gray, brown, olive or black. It's 

 often marked by a distinctive pattern 

 of dark and light concentric circles. 

 Its head and legs range from light to 

 dark gray with darker spots. The hind 

 legs are large; the feet, webbed, 

 making the terrapins powerful 

 swimmers. 



In the spring, diamondback 

 terrapins emerge from winter 

 hibernation spent buried in the mud 

 of tidal creeks or salt marshes. 

 Sexually mature adults mate in 

 March and April. The smaller male 

 can be seen clinging to the back of 

 the larger female during the courtship 

 ritual. 



Nesting occurs from April 

 through July. The female diamond- 

 back searches for a site to lay her 

 eggs, sometimes traveling more than 

 a mile from her aquatic home. The 

 reptilian mother lays her eggs during 

 the day, usually at high tide on marsh 

 islands, coastal dunes and road 

 embankments. 



As development has encroached 

 on habitat, nesting sites are often 

 separated from marshes by roadways, 

 which can mean death to the slow- 

 moving terrapins. Along Georgia's 

 barrier islands, turtle-crossing signs 



caution motorists to watch for the egg- 

 bearing mothers. 



After testing the sand with her 

 snout, a mother turtle will dig her nest 

 in the sand with first her front feet, 

 then her hind ones. She will drop four 

 to 18 pinkish- white, leathery eggs into 

 the flask-shaped nest, then cover it 

 with sand and leave. 



Unfortunately, the mother 

 diamondback terrapin is rarely alone 

 in her sandy delivery room. Gulls and 

 crows roam overhead or perch on 

 nearby tree limbs waiting for an 

 opportunity to feast on the newly laid 

 eggs. Gulls will snatch the eggs as 

 they are laid; crows dig up the eggs 

 after the mother has finished her labor. 



Gulls and crows are daytime 

 predators. At night, foxes and rac- 

 coons raid the nests for a midnight 

 snack. Some researchers estimate that 

 50 percent to 75 percent of the 

 diamondback terrapin nests are 

 destroyed each season by natural 

 predators. 



The hatchlings are also vulnerable 

 to predation. In one study, herpetolo- 

 gists found that 22 percent of the 

 hatched turtles were killed by preda- 

 tors. Even as adults, the terrapins are 

 eaten by raccoons. It's a small wonder 

 that any of the turtles reach their life 

 expectancy of more than 40 years. 



Terrapin eggs incubate 50 to 100 

 days before hatching. Temperature 

 determines the length of the incuba- 

 tion period and the terrapin's gender. 

 Warmer temperatures yield more 

 females, and cooler temperatures 

 result in more males. 



Once diamondback terrapins 

 hatch and travel to the estuary, a 



20 MAY/JUNE 1995 



