Turtle Journal

Terrapin Hatchling “J.P.” Ready for Release 

It’s no life of leisure spending time in the recovery lab.  We expect each hatchling to return to the wild in better condition than when it arrived.  Normally that process involves heat and hydration and ample safe space to exercise its limbs in swimming and crawling.  The baby terrapin discovered in a Lieutenant Island basement yesterday took exercise to the extreme, doing one limb (hand) push-ups, Jack Palance style.  After such a feat of physical prowess, he earned the name “J.P.” and also won his release into the nursery marsh off Turtle Point this morning.

Turtling in Blackfish Creek

Temperatures remained quite cool for the end of May and a stiff northwest wind continued to churn Blackfish Creek into an inky mix.  Few turtles were observed flowing with the noon low and only one was captured when the tide reached full ebb.

Male Terrapin #1076 Heads Back into Blackfish Creek

Terrapin 1076 is a good size, mature male.  He measured 12.6 centimeters carapace length and weighed a hefty 330 grams.  Like many of our recent captures, he had mud caked inside his frontal cavity and along his rear side.  He also had light green algae rimming his rear marginals and under his chin, too.  All indications seem to point to a delayed or stuttered start for the Wellfleet Bay terrapin population in 2001.  We need to wait for the kick-off of nesting as a second benchmark to gauge 2001.

While raising the flag this morning under bright sunshine and a snapping southwest breeze, I was visited by Bill Walker, a summer resident on Lieutenant Island and member in good standing of the Paludal Posse.  Last year, he and his wife Florence found a female nesting in their driveway — a good 1/4 mile uphill trek from the nearest marsh.  That protected nest yielded a dozen perfect hatchlings in the fall.

Terrapin Hatchling Over-Wintered in Bill Walker’s Basement

Today Bill had another story to tell.  Just back for the summer, he was cleaning the basement and swept up a “stone” that decided to start moving when it felt the broom.  He picked up a 2.66-centimeter, 5-gram diamondback terrapin.  Examining the walk-in basement from the outside, I found a small space under its wooden doors through which a baby turtle could wander.

Diamondback Terrapin Hatchling with Beautiful Gray Eyes

This foundling was a long, long way from safety in the marsh.  And thanks to the Walkers, she’ll now have a chance to make it in the wild.  Quite an attractive critter, she had unusually light gray eyes around a dark pupil.

Diamondback Terrapin #1075 with Large Male Tail 

In Blackfish Creek this morning, we found terrible visibility caused by several days of southwest winds and thunderstorms churning up the bottom.  We also found a mature male turtle (#1075) seen for the first time.  He measured a little over 12 centimeters and hit the scales at 282 grams.  Turtle 1075 sported a stylish Poirot-esque mustache, was still heavily caked in mud, showed pocks and minor scarring of his plastron, and a hard sore on the underside of his right rear limb.

Kids Help Release Terrapin #1075 into Blackfish Creek

The highlight of the day, though, was a chance to indoctrinate some new recruits for the Paludal Posse.  Joe, Kira, and James happened to be visiting the island from the mainland with their parents, saw our research activity, and had the good sense to join in the fun.

Thunderstorms Pound Wellfleet’s Blackfish Creek 

Wedged between waves of violent thunderstorms, we managed a few moments of terrapin observation in Blackfish Creek this morning.  As we arrived on Lieutenant Island and gathered gear for over-dune trek to the rip, the field phone rang with an urgent message from Bob Prescott, director of the local Mass Audubon sanctuary.  “I just looked at radar and a band of thunderstorms has taken aim on Wellfleet.  If you’re in the water, get out.  If you’re not, stay put.”  Sound advice, indeed.  The raw beauty of thunderstorms skimming across the bay is a sight to die for, but standing knee deep in water on the tidal flats (and there’s a reason why they’re called “flats”), while holding a dip net with a 10-foot metal rod, tempts the fates to extol the “die for” price of admission.  We hunkered down inside the jeep as lightning ricocheted around us.

Terrapin Gender Dimorphism Models:

Female #697 and Male #823

In a lull between bands, we raced across the channel and took position in the rapids.  The once pristine beach was strewn with slimy algae of all shapes and shades, as the overnight storm churned the bottom.  Water color and visibility matched the blackened sky.  But as luck would have it, and it usually does, Terrapin 697 swam right through my legs and into the net.  She is an old friend with a remarkable story to tell.

First observed in June of 1997, she had crawled out of Blackfish Creek to nest in an upland dirt road on Old Wharf Point.  Around 10 years old, she measured 16.70 centimeters carapace length and weighed 806 grams.  The next time we saw #697 proved traumatic.  On 1 July 1998, she was hit by a car and left at the side of Route 6.  The front of her carapace was broken, as was her plastron, and she was ambulanced to Wildcare for emergency treatment.

Shell plastered, she was released into Blackfish Creek with but faint prayer that she would survive.  Yet, on 13 September 1999, Turtle 697 (on the left) was netted while paired with Male #823 (right).  Her shell, though looking a bit dinged, had healed quite well.  And now the picture of this “adorable couple” serves as our lecture slide for illustrating gender dimorphism in diamondback terrapins, never mind offering a poignant vignette about the dangers of vehicles during nesting season, the importance of quick and positive intervention, and the incredible resilience of turtles — all with a nice happy ending.

Female Terrapin #697 in 1999 (Left) and 2001 (Right) 

Today’s observation merely punctuates to the story.  Number 697, as shown by these carapace photos from 1999 and 2001, has continued to improve.  It is no surprise that she has not grown much during this traumatic healing period.  She measures 16.8 centimeters long and weighs 846 grams.  But, all in all, not a bad outcome for a critter who had been so badly injured.  It was worth dancing between lightning strikes to meet her once more.

The (Most) Northern Diamondback Terrapin

Northernmost Diamondback Terrapin Hatchling Found

We lucky researchers in Wellfleet Bay let the words “the northernmost population of diamondback terrapins” roll glibly off our lips.  But in any “northernmost” habitat, there must be one spot, one location which is north of all the rest.  So it is in Wellfleet Bay, too, as the dike blocking the mouth of the Herring River defines the most northern accessible latitude in the entire harbor.  Today a family, driving Chequesset Neck Road to its northwest dead end at Cape Cod Bay, found a hatchling crossing in front of their car (see red turtle on map below).  They brought it to the Mass Audubon sanctuary to identify its species.  You guessed it: the Northern(most) Diamondback Terrapin.  They simply can’t get any farther north, as her mother had trekked north up a dune and inland to nest on the far (north) side of the asphalt road.

Northernmost Diamondback Terrapin Hatchling

Hatchling 008-01, who pipped in the fall but opted to remain over winter in her underground nest chamber, stretched out to 2.8 centimeters carapace length and weighed 6 grams.  Far from dehydrated, she was bright-eyed and frisky, in a hurry to get a jumpstart on the season ahead.

Northernmost Terrapin Hatchling Released into Herring River Marsh

I released Hatchling 008 at the head of the National Sea Shore trail to Great Island at the Gut — a tombolo which now converts the island into a peninsula.  After enduring waves of weekend walkers who ooh-ed and aah-ed, snapped pictures, and suffered my lecture on conserving terrapins, she ambled eastward into the marsh, crawled under a dense layer of beach grass, and disappeared from sight.

Blackfish Creek Rip at Low Tide

A break in the weather graced the morning with warming sunshine and a refreshing southeasterly breeze.  Water temperatures reached 60 degrees — again.  And terrapins, which had already awoken once from brumation, have dug out of a second time following a mid-May sleep-in.  While still not moving in large numbers, turtles have resumed their semi-diurnal tidal parade through Blackfish Creek. 

 Female Terrapin Caked in Brumation Ooze

Four terrapins were netted coming through the rip, two males and two females, all of whose cavities were caked in mud indicating recent emergence.  Passing through the rapids twice daily cleanses our turtles quicker than a front-loading, tumbler washing machine.  Two of today’s terrapins, the males, had been seen earlier this year, one on May 1st and the other on May 3rd.  The two females were first-time captures.

Female Terrapin $1074 Shows Blood Beneath Plastron

A disturbing observation was made on the plastron of female #1074, and to a lesser degree of male #1056, too.  There was a bright redness visible beneath the plastron scutes, which looked like bleeding.  [Editor’s note from March 2010:  After more than a decade of observations, this sub-plastron bleeding is noted in mature female diamondback terrapins in mating aggregations before nesting.]

 Male Terrapin #1056 Algae Gain Since May 3rd

Terrapin 1056 also showed how quickly these turtles can build up algae growth.  You’d hardly believe it was the same critter when you compare the 3 May photo on the left with today’s view.  On the other hand, chilly temperatures have probably kept him fairly inert the last couple of weeks.

Albany Visitors Release Terrapin Hatchling in Nursery Marsh

Finally, Memorial Weekend signals the return of summer volunteers to our Paludal Posse.  One couple stopped me on the causeway as they arrived from the mainland.  “How did our turtles do?”  These folks had found a terrapin laying a too shallow nest in their driveway last 29 June.  The eggs were relocated to a protected site.  “I guess no one will ever know?” they shrugged in disappointment.  Not so — I gave them baby pictures of their hatchlings as they emerged in late September.

Another refugee family from urban Albany called this morning with a surprise.  Two teenage guests found a hatchling in the wrack just outside their cottage — a prime nesting area on Lieutenant Island.  This baby was just 2.65 centimeters long and tipped the scales at 5 grams.  She had fully absorbed her yolk sac, and unlike the hatchlings found last week, she was not dehydrated.  Perhaps this long string of rainy days did some good after all.  Following a quick assessment of her health, this tiny dynamo was released back into the marsh by her finders — the newest volunteers in Wellfleet Bay’s Paludal Posse.

Is This Outfit Appropriate to Capture Cold-Blooded Animals? 

When on 22 April turtles began emerging from their winter sleep, and by 1 May when water temperature over the tidal flats had reached 72° Fahrenheit, it seemed the terrapin season had sprinted to a record start.  We should know better.  After ten days of persistent easterly winds blowing off the North Atlantic and storm fronts smothering the Cape in grayness, water temperatures have plummeted.  This morning’s reading barely hit 55°F, the apparent threshold temperature in Wellfleet Bay for terrapins to enter and leave brumation.  Yesterday not a single female was seen swimming through the channel nor had one been captured in Blackfish Creek this entire week.  Research assistant Maureen Ryan, who reported for duty from college in Wyoming on Tuesday, wondered aloud what had become of those balmy swimming trunk days I wrote about in early May.  Was it some cruel hoax?  If so, the turtles weren’t laughing.

Two Females and a Male Terrapin Return to Blackfish Creek

The three terrapins captured this morning were all caked in mud as though they had just emerged from brumation.  Yet, all three had already been seen this year.  Female 920 came through the rip paired with a male on 23 April; male 720 swam the channel on 29 April.  Terrapin 1006, another female, was spotted on both 5 and 10 May.  So, it was a surprise to see them all painted in mud, cold to the touch, and acting very sluggish.

Number 720, the male on the right, and #920, the female on the left, have both acquired a ring of light green algae clinging to their marginal scutes.  Both had absolutely clean carapaces when photographed in late April.

Female Terrapin #1006 Slips into Blackfish Creek

The change in Terrapin 1006 was equally dramatic, although not physical.  Her behavior had completely changed in the last two weeks.  When first observed on 5 May, she was described as “quite active”; on the 10th, she was termed “aggressive.”  Today, though, she was passive and sluggish.  She moved through the rip so slowly that no net was needed to capture her.  She could barely maintain controlled headway.