Posts Tagged ‘Diamondback Terrapin’

Skill + Luck + Patience Yield Best Dune Emergence Sequence

Monday, September 22nd, 2008

Skill brings you to the precise location where an extraordinary event MAY occur.  But luck ensures that you reach that spot at the once-in-a-lifetime moment when an extraordinary event DOES occur.  Finally, patience permits you to dwell at the right spot at the right time for that exact instant when everything comes together and a miracle happens.  Watch how these factors brought us to the perfect dune emergence sequence on Saturday.

Hatchling Slaloms Down High Dune

Experience keyed us to a certain set of dunes that lay within a dense diamondback terrapin nesting site.  Skill enabled us to recognize a series of fresh hatchling tracks that crisscrossed the dune face like trolley lines (see above).  But then luck kicked in.  It showed us a stream of tracks that appeared to converge on a single concavitiy in the dune slope (see below). 

Tracks Converge at Possible Emerging Terrapin Nest

Patience gave us to time to wait and to watch the concavity without barging into the scene and disturbing the ongoing miracle of birth.  Seconds ticked by, then minutes, and finally a head poked through the shifting sand … and another one.  Hatchlings popped like slow-motion popcorn under the heat of the midday sun.

Hatchlings Emerge and Scramble to Safety

Spying so many tracks when we arrived, we had hoped that perhaps one hatchling might be left to emerge.  As luck would have it, ten babies remained in the nest and they popped out in ones and twos over the next hour.  As a whole, the event proved our very best documented dune emergence sequence as a beautiful miracle unfolded before our eager camera lens.

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Best Terrapin Hatchling Emergence Sequence

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
 

Eastern Box Turtle Hatchlings

Wednesday, September 3rd, 2008
Gardening can yield some unusual crops. A resident of Paine Hollow in South Wellfleet was clearing the plantings around her cottage when she discovered a hole in the mulch covered bed. At the bottom, four perfectly healthy, but grumpy Eastern box turtle hatchlings were hunkered down for an overcast, windy and raw September day. 

Four Eastern Box Turtle Hatchlings

They seem small … that is, until you compare them to diamondback terrapin hatchlings that emerged a short distance away.

DBT & EBT Size Comparison

Comparison of Terrapin (Left) & Box Turtle (Right) Hatchlings

These hatchlings were discovered at the edge of conservation land, the Whale Bone Trail, that I had assesssed last fall as prime Eastern box turtle habitat.  What a beautiful way to have your assessment confirmed!

Eastern Box Turtle Hatchling Close-Up

“All Work and No Play” Hatchling Style

Tuesday, September 2nd, 2008

Yes. Hatching, emerging and dashing into hiding is very serious business for diamondback terrapin hatchlings. One mis-step and you become a predator snack. Still, that’s no reason to avoid an opportunity for a little fun en route to the safety of the nursery salt marsh.

Terrapin Hatchling “Playfully” Slide Down Dune

The Hatchling Also Rises

Wednesday, August 27th, 2008

A diamondback terrapin hatchling emerges from its Turtle Point nest and begins its scramble into the safety of the Lieutenant Island nursery marsh.

Lone Hatchling Slowly Emerges & Heads to Safety