Abstracts of Papers
Reproductive Patterns of the Northern Diamondback Terrapin
Christina F. Watters
The northern diamondback terrapin (Malaclemys terrapin terrapin) is one of seven subspecies of diamondback terrapin that are found exclusively in coastal salt marshes along the Atlantic and Gulf coasts of the United States. Terrapins are highly aquatic and very cryptic; therefore, many aspects of their life history, including reproduction, are poorly known. Long term research studies at the Wetlands Institute have allowed us an opportunity to gather information on various aspects of local terrapin nesting behavior including: length of the nesting season, average clutch size, average size of emerging hatchling terrapins, incubation time and over-wintering of hatchling terrapins in their nest chamber. In addition, we have documented nest site fidelity from year to year, diurnal and nocturnal nesting, double and triple clutching (laying more than one clutch of eggs in a single season), and the interval between successive clutches. These studies were supported by the Wetlands Institute and by NSF Grant DBI-REU-0097635.
Analysis of Northern Diamondback Terrapin,
J. L. Woerner,1 L. Landis,1 and R.C. Wood 1, 2
Increased motor vehicle traffic on the causeways between the mainland and the barrier islands of coastal southern New Jersey is a growing threat to diamondback terrapins. Development on the barrier islands has destroyed most of the sand dunes that originally served as the primary nesting site for terrapins. With the disappearance of sand dunes, females have had to find alternative nesting grounds, which have proved to be the shoulders of roads crossing and adjacent to their native salt marshes. Embankments of causeways have thus become a dangerous substitute for sand dunes, resulting in hundreds of terrapin road kills annually. Each nesting season, researchers at the Wetlands Institute have patrolled a transect on the Cape May Peninsula of southernmost New Jersey in order to collect road-killed terrapins and remove potentially viable eggs. These eggs are incubated and the hatchlings are cared for until they grow large enough to be predator proof, at which time they are released. Typically, 200-300 hatchlings are repatriated each summer. However, 400 to 600 adult female terrapins are killed on the roadways in Cape May County each year. Hence, there is a substantial net loss to the local terrapin population annually.