Posts Tagged ‘Outer Cape’

Rescuing Live Hatchlings from Maggot Infested Nests

Wednesday, September 10th, 2008

No, it’s not a pretty thought.  It’s not a pretty sight and it’s certainly not a pleasant experience.  But it is the real world of terrapin conservation and so for the serious naturalist, it’s a necessary learning moment.  Be thankful that the pictures are two dimensional and that there is no smell-vision key on the video clip.

Research from September 2000 revealed for the first time that a significant percentage of diamondback terrapins nests in the Wellfleet Bay system were being destroyed  by fly maggots.  The infestation appears to begin at pipping when hatchlings poke openings in their eggshells allowing the odor of organic material to escape and to attract flies.  Since Outer Cape hatchlings remain in their shells and underground for several days after pipping, maggots have the opportunity to attack an extremely vulnerable prey as the maggots work their way through the cracked shell to devour the exposed hatchling.

Pipped and Vulnerable (Upside-Down) Terrapin Hatchling

In most cases, the maggots begin with the umbilicus and enter the main body of the living hatchling through the yolk sac, hollowing out the baby from within.  Thus, hatchlings and whole nests are destroyed by these insidious predators underground without ever being exposed for counting by researchers like nests preyed upon by more obvious predators.

Maggots Attacking Helpless Hatchling (Rescued)

Observations over the last nine seasons confirm the 2000 discovery and underscore the severe constraint this predation places on the number of live hatchlings that emerge on the Outer Cape each year.  This season (2008) alone has seen more than half of all nests in the critical habitat of Lieutenant Island infested with maggots.

Maggots Consume Hatchling Embryo

Thankfully, the aggressive conservation protocols developed after the 2000 discovery have rescued more and more hatchlings each year from this infestation.  By checking nests as they begin to pip and harvesting them at the first sign of maggots, our efforts have significantly increased the number of live hatchlings entering the system since the turn of the millennium.  Even after the infestation has begun, our actions can save most hatchlings from the most heavily infested nests.  We harvest the pipped eggs and remove all maggots before re-burying premature hatchlings in clean, moist soil to finalize the incubation process.  These efforts have rescued thousands of hatchlings that would never have seen the light of day.

Hatchlings Rescued from Maggot Infested Nest

This particular nest on Turtle Point gave away its location by a concavity on the surface.  As hatchlings pip and squirm around inside the egg chamber, sand gets displaced and this underground activity shows itself as ripples of the surface sand to the most seasoned turtle researcher.  We were able to rescue 10 baby hatchlings from the devouring horde of maggots in this nest, hand-picking tiny maggots from limb cavities and off yolk sacs, then bathing the hatchlings in clean, fresh water for rehydration before release.  So, a good day in the Land of Ooze where we saved an order of magnitude better than our goal of one turtle at a time.

Two-Ton Vehicle Versus Quarter Ounce Hatchling

Sunday, September 7th, 2008

Due to human development and associated pressures, some of the best remaining nesting sites for diamondback terrapins on the Outer Cape are one-lane dirt roads that abut salt marsh nursery ecosystems for hatchlings. Obviously, roadways are extremely dangerous for the female as she spends more than 30 minutes digging her nest, depositing her eggs and covering it once again.  Because these compacted roadways are so hard, and her nest sculpting creates a natural arch to spread the load of vehicular traffic, the eggs appear to do fine through June, July and August as they incubate under the summer sun.

Female Terrapin Nesting in Middle of Dirt Road

But when hatchlings begin to pip and squirm about in the nest, and when one or more begins to tunnel to the surface leaving an emergence hole in the road, then the architectural integrity that served so well during incubation is compromised.  Weight no longer is evenly distributed, and the egg chamber compresses and begins to collapse under the stress. 

Emergence Hole in Middle of Marsh Road on Lieutenant Island

I discovered this little (3 gram) hatchling wedged under the lip of the nest that had been collapsing under the day’s traffic.  Two of its siblings had already been crushed in the center of the egg chamber.

Premie Hatchling Distorted by Road Traffic

In addition to problems with its distorted shape, its eggshell had been invaded by fly maggots that were trying to find a vulnerable orifice to invade.  I had to hand-pick these nasty predators from the tiny hatchling.  Based on experience, I know that this critter will now do quite well.  With a little time, some warm hydration and a bit of TLC, its shell will resume a normal shape and it should be ready to be released into the wild within a few days to a week.

Emerged Terrapin Hatchling Run Over on Marsh Road

I wish the same could be said for another sibling (above) that I found a foot outside the nest and squished in the south tire track of the dirt road.  It’s a dangerous world for a turtle hatchling.  Few survive to tell the tale of their harrowing youth.  But with a little luck and a guardian angel or two, one turtle at a time can be saved and the whole world along with it.

Close-Up of Rescued Distorted Hatchling

Two-Headed Diamondback Terrapin Hatchling

Thursday, August 28th, 2008

In late August, a two-headed terrapin hatchling emerged from a nest in Eastham on the Outer Cape. Except for two heads, of course, the shell appears normal with an enlarged, split nuchal on the carapace and an extra, middle gular scute on the plastron. The left head seems to control the left two limbs and the right head appears to control the right two limbs.

Click Here to View Video in High Quality

Two-Headed Terrapin Hatchling from Eastham, MA