Posts Tagged ‘turtle point’

Tiny Hatchling Beats Cold Front by a Nose

Wednesday, October 22nd, 2008

Three Gram Second-Chance Terrapin Hatchling

“There’s always one more.”  That’s the motto of the Paludal Posse, our terrapin research and conservation team on Outer Cape Cod.  There’s always one more nest to find, one more nest to hatch, one more turtle in the nest, one more hatchling to emerge, one more turtle to save.  In short, there’s always one more.  And so it was proven again this weekend as we prepared our last batch of terrapin hatchlings for release on Tuesday, a promised mild October day.

Terrapin Hatchling and Second-Chance Egg from Nest 996

Sue counted 20 second-chance hatchlings soaking in 70F water to prepare for their sprint to freedom.  Second-chance hatchlings?  What the heck are second-chance hatchlings?  As we harvest emerging nests that have mostly hatched and other nests that have been exposed by predators, we often find a couple of unhatched eggs left behind.  Most of these eggs are in good shape and need only a couple days more incubation.  A few, though, look pretty sad; dimpled, dented, dehydrated, discolored, and so on.  These eggs wouldn’t make it in the wild.  Still, we prefer to give every turtle egg a chance even if it has only a small probability of survival.  So, these long-shot eggs go into our mystical, magical second-chance bucket, filled wtih clean, moist natal sand and warmed first naturally in our sun room until early October and then under a heat lamp in our lab until successfully hatched or all hope is exhausted.  We always have Halloween hatchlings, usually have Thanksgiving babies and occasionally find a pair of cute dark eyes staring up at us on Christmas morning.  (ASIDE:  Can there be a more powerful holiday message?) 

So, as Sue collected the 20 lucky babies for their trip back into the wild, she scanned the second-chance bucket and yelled in exclamation, “We’ve got another one!”  To which I sagely replied, “Yep.  There’s always one more.”

Perfect October Day for Second-Chance Hatchling Release

We made it to Turtle Point on Lieutenant Island while the weather held; 63F, gentle breeze and warming sunshine.  But a careful look at the clouds streaming above reminded us that a storm front approached. 

2nd Chance Hatchling and 20 Siblings Released at Turtle Point

The sand at Turtle Point had baked through the morning and reflected warmth as we sat down to release our 21 charges.  Placing them in a single bunch near the wrack line on the downward sloping dune, we watched as they scattered in random directions and power bursts.  Soon they had all disappeared into the nursery surroundings, some into upland vegetation, others into downland wrack and Spartina salt marsh, and still others burrowed into the warm dune sand.

Last Sailboat Dances with Northeast Blow in Blackfish Creek

Within an hour the weather had closed in.  The cold front arrived with gusts whistling across the narrow Outer Cape peninsula from the North Atlantic.  Clouds massed and grayed; white caps appeared; and we were doused in cold droplets whether from rain or briny spray we couldn’t tell.

“There’s Always One More” Egg in Second-Chance Bucket

Back in our warm, comfortable lab office Tuesday evening we inventoried our terrapin assets.  Tanks empty and ready.  Second-chance bucket filled with potential.  And our hopes high for one more miracle.

For Some Hatchling, Nursery Lies in the Uplands

Thursday, September 11th, 2008
 
One surprise we discovered over the last few years is that diamondback terrapin hatchlings employ a variety of strategies to survive their most vulnerable first year.  We had all expected that like sea turtles, terrapin hatchlings scramble from their nests in a beeline for the safety of the thick, rich, robust nursery salt marsh habitat ringing Wellfleet’s most productive nesting sites.  The first indications that we may have been hasty in this assumption were hatchlings we found in May and June each year heading DOWN HILL from the uplands toward the salt marsh.  The first few observations were dismissed as late emerging hatchlings that had overwintered in their natal nests since we had documented a few nests in May and June that had hatched in the fall, but where some hatchlings had remained until the next spring.  However, once we spotted yearlings heading down slope from the uplands to the marsh this rationalization collapsed.
 
Dr. Barbara Brennessel of Wheaton College conducted experiments tracking headstarted hatchlings released in their natal habitat in the Wellfleet Bay system.  They were equipped with a transmitter for RDF (radio direction finding) tracking.  Although much larger than a normal hatchling due to overwinter feeding, a number of these turtles headed into the salt marsh, behaving precisely as we would have expected a baby terrapin to act.  They hid out in the thick Spartina patens, feeding on whatever small critters they could discover in this rich marsh system.  However, some number of these headstarts went upland into the vegetated banks abutting sandy nesting areas and the salt marsh.  Since these animals were not “pristine” hatchlings, we asterisked their “aberrant behavior.”
 
But once we began to track baby hatchlings emerging from natural nests on treks upland, we realized that putting all the data together, many hatchlings race into the robust Spartina patens of the Wellfleet salt marsh system, lots of hatchlings dash under the rimming wrack line between sandy nesting banks and the salt marsh, and still others scale the banks and dunes to explore the vegetative uplands above the most productive nesting sites.  These terrapins employ a richer, more complex strategy that offers multiple opportunities for survival of hatchlings in a very raw and unpredictable climate at the northernmost edge of their range.
 
This week we watched the emergence of a nest at Turtle Point.  Ten live hatchlings left the nest and we followed them with a long-distance telephoto lens to determine how this group might behave once they had tunneled out of the nest.  You may recall earlier reporting of tracking hatchlings into the wrack line and others into the Spartina patens (see Tracking Terrapin Hatchlings, http://www.turtlejournal.com/?p=225)
 
The first hatchling set out on a solo trek and headed immediately into the vegetation above the nesting bank.
 
 
Solo Hatchlings Climbs into Upland Vegetation
 
Three others seemed to wait for this scout to complete its scramble, and then they too scaled the bank to disappear into upland vegetation. 

Three More Hatchlings Scramble Upslope

The last batch of six hatchlings followed suit, with the final two in this pair offering quite a tag team performance.
 
 
Final Six Head Upland, Too
 
Finally, once they had fully dispersed into the uplands, we attempted to find them again.  Truth be told, even though we had followed their movements in detail with a long distance telephoto lens, we could only locate four of the ten hatchlings because they were so well camouflaged within the groundcover vegetation.
 
 
Hatchlings Camouflaged in Upland Bearberry Vegetation