OUR NATURAL WORLD: IN THE FIELD
The sun is fast disappearing beneath the clouds, turning their undersides a delicate pink, as Kerry Muldoon hurries past the visitors center at the Jamaica Bay Wildlife Refuge.Facing a stiff wind – the remnants of a fall nor’easter – the biologist heads down a gravel pathway until she reaches a gentle slope delineated at its top and bottom by rows of aluminum flashing. Each pokes a few inches from the sand like a miniature fence.
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Sometime earlier in the day, Muldoon hopes, light brown disc-shaped creatures no bigger than a quarter will have wandered along the low fence lines and fallen into regularly spaced, half-buried, plastic quart jugs. And with any luck, Muldoon will find within her deceptively simply traps another tiny diamondback terrapin hatchling.
Chief suspect: raccoons
Over the past decade, Jamaica Bay’s diamondback terrapin population has declined “drastically,” she says. No one knows why the tidal marsh-dwelling turtles have fared so poorly, though researchers believe raccoons have done the most damage by digging up deep terrapin nests and eating the eggs or by munching on the hatchlings themselves.
Muldoon would like to know where the survivors go when they leave the nest. Do they crawl toward the sea or toward vegetation? Most turtle hatchlings instinctively head toward the nearest water, but early indications suggest that diamondback terrapin hatchlings at Jamaica Bay may be doing just the opposite – a surprising finding that only has raised more questions.
Are they trying to avoid marine predators? Might the water be too cold for them? And does their unusual migration from the nest make them more vulnerable to land-based predators such as raccoons? Someday the answers to these questions could help wildlife managers better protect the terrapins.
Muldoon, who is pursuing her master’s degree in biology at Hofstra University under the tutelage of herpetologist Russell Burke, occasionally sees tracks of the prime suspects in the sand.
“I get really mad,” she says. “I’m like, ‘Get away from there! Get away from my turtles!’”
Usually, though, it’s already too late. Earlier in the week, she discovered the aftermath of a raccoon attack at one of her study sites, with pieces of eggshell littering the sand like shards of porcelain.
The shells are still clearly visible in the waning light as she begins peering into the site’s tarp-covered traps. A small mirror allows her to inspect the far reaches of the jugs she has buried lengthwise, where the confined terrapins should have a better shot at escaping the searching paw of a raccoon.
If she finds a hatchling – an increasingly rare occurrence this late in the season – she records its location, marks its carapace, takes its measurements, snaps a few photos and then lets it go.
A lucky find
Nothing stirs in the upper line of traps. Muldoon shifts to the lower row as the western sky turns a dull orange.
Finally, at the very last set:
“Oh, we got lucky!” she calls.
From a jug, she retrieves a sand-encrusted youngster and places him on the palm of her hand. It’s the first one she’s caught in more than a week.
Each hatchling seems to have its own personality, Muldoon says. “Some are really eager to go and wiggle around a lot.” Others are shy, preferring to stay in their shells. This one poses motionless beside a nickel (a quick size comparison).
Kneeling by a long-dead horseshoe crab, Muldoon dons a pair of blue and yellow gloves embroidered with green turtles. She wears the gloves to avoid depositing too much of her own scent on the terrapin lest a raccoon associate the smell of humans with food. She has misplaced her felt-tipped marker, so she dabs a blob of white-out onto the hatchling’s carapace in case she comes across the same animal again this year.
After a few pictures and some notes in her notebook, it’s time to let her captive go. The raccoons will be out soon and Muldoon is loathe to leave the terrapin exposed, so she digs into the wrack line of decaying seaweed and debris deposited by the tides.
At least temporarily, the hatchling will trade the buried milk jug for a shallow nest near the jutting shell of another horseshoe crab, sheltered for the most part from the wind that continues to howl across the bay.
BY BRYN NELSON
Newsday Staff Writer
For more information, visit http://people.hofstra.edu/