Turtle Journal

Northernmost Diamondback Terrapin

For more than a decade, Turtle Journal has teamed with local residents of Outer Cape Cod and partnered with Mass Audubon’s Wellfleet Bay Wildlife Sanctuary to restore the region’s threatened population of northern diamondback terrapins (Malaclemys terrapin terrapin).  These elusive coastal turtles have thrived in the salt marsh systems of Cape Cod for centuries, if not millennia, only coming under existential pressure since the arrival of European settlers and most recently the press of human development into their fragile marsh environment and its abutting sandy uplands.  Thankfully, for these magnificent reptiles, intense human exploitation of the Outermost Cape came late enough to allow a small remnant population to survive and affording us the honor to restore it.  In neighoring regions such as Massachusetts’ South Coast, civilizaton and modernity have nearly wiped out diamondback terrapins from the habitat.

Freshly Laid Diamondback Terrapin Egg

Not willing or able to settle the long standing argument of which came first the turtle or the egg, Turtle Journal will simply assert that our successful restoration of the Outer Cape terrapin population began with protecting eggs, whether being carried by females or buried in the ground.  We focused our conservation initiative on preventing disturbance, injury and death to female terrapins lugging their eggs landward to their natal nesting sites, on finding nests before the predators, and on protecting about 5% of nests from incubation to hatching in the late summer and early fall.  We hypothesized that substantially increasing live hatchlings entering the nursery habitat would result in a dramatic increase in recruits into the sub-adult and adult population.  This hypothesis proved as correct in practice as it did on the drawing board.  Starting withs 9 gram (1/3 ouce) eggs we would create a new world of terrapins.

Freshly Depredated Diamondback Terrapin Egg

We never intended to stop all predation.  After all, the mammal population of Outer Cape Cod depends on turtle eggs to feed their spring born young.  And turtle survival strategy depends on over-producing eggs on the likelihood that as high as 99% of eggs and hatchlings will be consumed by predators before reaching adulthood.  Our goal was to modestly protect perhaps 5% of nests and to assist the successful offspring of natural, unprotected nests to reach the safety of the nursery salt marsh in the fall.  Still, on an emotional level, seeing a terrapin egg destroyed by a predator creates a bit of anger and frustration even in the most scientific of the Turtle Journal team.

Protected Diamondback Terrapin Nest on Outer Cape Cod

On the other hand, what brings unbridled joy to Turtle Journal is the accumulation of protected terrapin nests along the uplands of Outer Cape Cod with tiny blue flags snapping in the summer breeze.  They offer the promise of survival for the northernmost diamondback terrapin population.

Outer Cape Terrapin Nesting in Tire Tracks

Protecting egg production means protecting mothers.  Some of the favored nesting locations for terrapins on the Outer Cape are dirt roads, especially on sandy Lieutenant Island which has become the densest nesting spot for terrapins perhaps in all of New England.  While obviously nesting in the middle of tire tracks on a well traveled summer road can be extremely life threatening for the mother who blends in perfectly with the surroundings, these dirt roads have proven extremely productive for hatchlings.  If the female can successfully bury her architecturally sound nest in the hard-packed dirt, our movement across the road with our cars, dogs and garbage keeps predators at bay.  Depredation rates in Outer Cape dirt roads can be one tenth the level of predation in isolated dunes.  Still, protecting these vulnerable females can be a challenge. We post signs and alert visitors, but the best protection for nesting terrapins comes from vigilant and pro-active residents.  Last Friday a great friend and long-time resident of Lieutenant Island literally threw himself in front of speeding workmen who were about to crush a nesting female.  Jim waved them off and quipped, “I’d rather have them hit me than her.”  Such is the support that these quirky diamondback terrapins have elicited from their co-inhabitants of the island.

 

Four Saved Eggs from Depredated Terrapin Nest

On Saturday, Turtle Journal discovered the first depredated nest on Lieutenant Island’s Turtle Point.  Crestfallen, we saw that the predator had largely wasted the protein, digging up the eggs, cracking them open, but abandoning them unconsumed.  Instead, an army of ants darted back and forth across the eggs collecting nutrients.  Turtle Journal checked the egg chamber of the depredated nest, and rejoiced in finding four intact, potentially viable eggs still tucked in the bottom edges of the nest.  Four eggs that may yield four fall hatchlings!  We cleaned and relocated the eggs to a new “salvage” nest where we will incubate eggs from partially depredated nests that we find during the next several weeks.

Northern Diamondback Terrapin

Every terrapin seems to have a story to tell … if we could only understand them.  This beautiful female nester from the Outer Cape wanted to tell the tale of how her nest at the dune off the Boathouse Beach path was discovered and protected by Turtle Journal in Saturday afternoon’s rain storm.

 

Tracking Turtles, Saving Nests

We reached Lieutenant Island’s “Hook” at the northeast corner in early afternoon.  Clouds had socked in and the morning’s drizzle had transformed into a hard rain.  Just to the east of the Boathouse Beach footpath, we spotted terrapin tracks that were rapidly disappearing in the downpour.  We could see how she had crisscrossed the dune, climbing up and slaloming down, stopping every few feet to dig a test hole as she looked for the perfect spot to deposit her eggs.  One spot looked particularly lucrative as the most likely site for her nest and our excavation yielded sixteen perfect pink eggs that had been freshly laid within the hour.

Nest 111 on Boathouse Beach Path Dune

Nest #111 with predator excluder cage and blue flag now marks the spot where these sixteen eggs will incubate through June and July and August.  We can all watch as the sun’s heat penetrates to the eggs, warming some enough to create females, leaving others as males, and finally incubating them enough to pierce their eggshell and emerge into a brave new world where terrapins once again thrive on Outer Cape Cod.

Chris, Courtney, Sam & Abigail Brown & Friends

Diamondback terrapins in the Taunton River?  Twenty-five miles from open water and tucked into a small protected bay ten miles from the mouth of the Taunton River, we find an isolated population of threatened diamondback terrapins more than 25 miles its closest neighbor. 

Assonet Bay Shores Beach Terrapin Nesting Site

Four years ago, Turtle Journal’s Don Lewis confirmed the existence of this terrapin population when he found forty hatched and depredated nests concentrated at Assonet Bay Shores beach on Wescott Island in Assonet Bay (see map above).  Since then, Turtle Journal has partnered with local resident volunteers to document these turtles.

Carl Brodeur Proudly Shows Terrapin Eggs

Leading the investigative team in Assonet Bay is Carl Brodeur of Arborcare with Ropes ‘n Saddles who lives on Wescott Island and has been a powerful advocate within the community for diamondback terrapins as a bellwether species within the bay to reveal the state of the local environment.  Carl captured the first terrapin specimen in Assonet Bay and has been actively engaged in documenting this local population.

Three Diamondback Terrapin Females at Assonet Bay Shores

On June 6th, Carl found three mature female terrapins coming ashore onto the beach at Assonet Bay Shores for a nesting run.  These beautiful turtles, all heavy with eggs, show the same general characteristics and size as terrapins found in Barrington, Rhode Island, the nearest known neighboring population 25 miles away … as well as those terrapins that have been observed in the estuaries of Buzzards Bay 40 miles to the southeast.

Sam Brown Release Terrapin into Assonet Bay

The Brown Family (see photo at top of posting), friends of Carl Brodeur, had the great opportunity to release these magnificent diamondback terrapins back into the waters of Assonet Bay in Freetown, Massachusetts.  For more information on Assonet Bay terrapins, see Release of Little Dude and Three-Year-Old Finds First Terrapin of Season in Assonet Bay.

 Sue Wieber Nourse Checks SouthCoast Nest Sites

More heat, more thunderstorms, more turtle nests … it must be summer on the south coast of New England.  The Turtle Journal team and volunteers investigated diamondback terrapin nesting sites from Outer Cape Cod to the Taunton River today.  A visitor to Lieutenant Island in South Wellfleet called the Mass Audubon Sanctuary to report that a terrapin had nested in the middle of Way 100 (Marsh Road), a one-lane dirt road along the south side of the island that has become one of the densest nesting locations in all of New England.  Carl Brodeur, Turtle Journal’s eyes and ears on the Taunton River, called to report he had captured a female on a nesting run at Assonet Bay Shores Beach in Freetown and that perhaps a dozen terrapins had nested the previous day on the beach.  Unfortunately, most nests had been depredated overnight.

 Freshly Depredated Terrapin Nest on Aucoot Cove

Sue Wieber Nourse and Don Lewis from Turtle Journal checked Aucoot Cove between Marion and Mattapoisett off Buzzards Bay this afternoon.  We found one freshly depredated nest with eleven still moist yolks.  Aucoot Cove serves as the largest nesting location that has been documented so far on the west bank of Buzzards Bay.

Aucoot Cove Nest with 14 Depredated Eggs 

Another nest at the elbow of Aucoot Cove contained fourteen recently depredated eggs, probably consumed by predators last night.  We found no turtles either at Aucoot Cove or Hammetts Cove on the east side of Sippican Harbor, probably because heavy winds and storm clouds have taken command of the afternoon sky.  Severe thunderstorm alerts and a rare tornado warning are in effect.

HELLO, FRIENDS.  Young Sean Whitkens is surrounded by turtles, courtesy of Don Lewis, Executive Director of the Massachusetts Association of Conservation Districts, during a recent lecture program on coastal turtles at Buttonwood Park Zoo.  PHOTO BY CHRISTINA STYANT/The Chronicle

“NEW BEDFORD – Known as “The Turtle Guy,” Executive Director of the Massachusetts Association of Conservation Districts Don Lewis recently delivered an informative and sometimes humorous talk on the “Turtles of Coastal Massachusetts” at the Buttonwood Park Zoo.”

A BIG TURTLE: Research scientist Sue Wieber Nourse lets youngsters attending a lecture on the Turtles of Coastal Massachusetts at Buttonwood Park Zoo have some hands-on time with the real thing.  PHOTO BY CHRISTINA STYAN

“Research scientist and master educator Sue Wieber Nourse, CEO of Cape Cod Consultants, was on hand to introduce several live turtles to the adults and youngsters attending the lecture.”

For the full story from the Dartmouth-Westport Chronicle, clink on the pictures above or the hyperlink on the newspaper name to the left.

Sue Wieber Nourse Discovers Fresh Terrapin Nest

Rumbles of thunder applauded Turtle Journal’s arrival on Lieutenant Island this morning.  Thick, rain ladened clouds scraped across the tree tops with a flash of lightning seemingly sparked by each touch.  Wellfleet Bay, which just yesterday appeared looking-glass smooth, broiled in white caps as receding tide clashed with southwesterly storm winds.  Luckily, the rain held back as we scoured Turtle Point for evidence that nesting females had emerged on the morning high tide preceding the thunderstorms.

Pink, Beautiful Freshly Laid Diamondback Terrapin Eggs

One daring female had crawled ashore from Fresh Brook Run, crossed a tenth of a mile expanse of thick salt marsh grasses, and crisscrossed the high dune at Turtle Point until she found her perfect spot to deposit the next generation of diamondback terrapins.  The sand showed three disturbed areas where she might have buried her clutch.  Don took one and Sue chose a second; the third would wait the results of the first two digs.  Sue Wieber Nourse picked wisely as her fingers probed the “sweet spot” where the female turtle had dropped her shaft into the wider egg chanber.

Turtle Journal Protects Threated Terrapin on Turtle Point

Sue excavated the nest and determined from color, texture and moisture of the eggs that they had been freshly laid this morning.  We assessed that the nest was perfectly situated to receive plenty of high quality sunshine with little risk of depredation by dune grass roots.  Sue carefully reburied the eggs, smoothed the sand and installed a cage over the nest.

Predator Excluder Cage Protect Terrapin Eggs

The predator excluder cage, held down by large metal staples, keeps most threats at bay.  We received an extra boost from the weather because as soon as the cage had been embedded  in the dune, the skies opened and a deluge fell.  A heavy rain often erases the scent of eggs that attracts predators like a dude ranch dinner bell.  Nests in this isolated location suffer a very high depredation rate, often greater than 90%.  Part of the reason for this high loss is compression of nesting into compact sites because of human recreational development on the island.  As nesting density increases, predators see Turtle Point as a smorgasbord to feed themselves and their spring-born offspring.

Protected 2009 Island Hatchling Eager for Release

To compensate for this pressure, Turtle Journal in partnership with Mass Audubon has protected terrapin nests on the island each year for the last decade to offset this unnaturally high predation rate.  Residents of Lieutenant Island continue to be the biggest supporters of the terrapin rescue and conservation program, and a large part of its success can be directly attributed to their enthusiastic support and pro-active efforts to protect “their turtles.”