RESEARCH CAN LEAD TO INTERESTING FINDINGS
remarkable coincidence associated with a road-killed turtle and her
eggs has made scientists reflect on the value of preserving wildlife
that cant seem to stay out of harms way.
at the University of Illinois conducts research on the U.S. Department
of Energys Savannah River Site in South Carolina. Several years
ago, with the help of numerous students and other colleagues, I began
doing research on turtles at the same site through the University of
Georgias Savannah River Ecology Lab. Over the years all of us
collectively have captured, marked for identification, and released
more than 30,000 freshwater turtles.
the most common species in the region is the yellow-bellied slider turtle.
When returning from a field site, Brett found a slider that had been
hit by a car on a highway. The turtles shell was badly cracked
but Brett rescued it and took it back to the lab to see if the injury
could be repaired. We often use superglue with great success to patch
together small cracks in shells of injured turtles.
turtle was in the lab she laid eggs and then died. Brett placed the
eggs on damp paper towels so they could be incubated in the lab. Turtle
eggs can be hatched if they are kept on moist material and at room temperature.
an injured turtle lay eggs in the lab is not that unusual, but the rest
of the story is noteworthy. As Brett was attempting to repair the shell,
he noticed three small notches, tiny scars on the plates that form the
edge of the shell.
old identification marks from our earlier turtle research. For decades
we notched the margins of the shells in combinations so that each individual
had a unique code, a sort of turtle Social Security number that would
allow it to be identified for its entire life.
realized that the turtle had one of the old identification codes on
its shell, he asked Brian Metts of SREL to check the turtle data files.
He wanted to know what he could learn about the dead turtles past.
Turns out she had hatched from an egg two decades earlier.
we know this? Brian was certain of the turtles age because this
female turtles mother had been picked up as a highway casualty
at the exact same spot 20 years earlier. The mother had died in the
lab but had laid eggs before she did so. Those eggs were incubated and
hatched in the lab.
our usual procedure, the baby turtles in the clutch 20 years before
had been given their own identification codes. They had then been released
as week-old hatchlings back at the wetland near the highway where the
mother had been found.
that had been previously marked have been recaptured as many as 20 years
later. But what are the chances of a road casualty resulting in offspring
that later suffered the identical fate as the mother? The odds exceed
lottery-level probabilities and raise some interesting questions.
a new batch of baby turtles into the wild, are we preserving ones with
a genetic predisposition toward crossing roads when its time to
lay eggs? Are we putting ourselves in the same category as well-meaning
people who push stranded whales and dolphins back out to sea?
mammals that beach themselves do not have a sustainable career as marine
leviathans. Should these particular turtles be left by the side of the
road if they are injured? In other words, should we help keep animals
in the gene pool if they cant make it on their own in todays
decided not to overanalyze the question of whether we are creating an
animal welfare dependency program for turtles, though we cant
help speculating. If any road-killed granddaughters of the turtle from
20 years ago end up in the lab we may know the answer.
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