Natural Lands - The Magazine of Natural Lands Fall/Winter 2018, Issue 153 | Page 8

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N ATUR A L L A NDS
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The bog turtle is North America’s smallest and rarest native turtle. Over
the last 20 years, about 50 percent have disappeared. Their dwindling
population—estimated to be as low as 3,000—is concentrated in eastern
Pennsylvania, New Jersey, and New York.
small wonder.
saving America’s rarest turtle.
There’s a conservation biology rule of thumb that, for a species to have
enough genetic diversity to survive for another century, it must have a sta-
ble population of 5,000… bad news for bog turtles. However, a recent study
offers hope, suggesting that the turtles can survive with only 40 adults.
But it all comes down to private landowners taking steps to protect the
land these turtles call home.
Here’s the good news: Bog turtles
are long lived—up to 50 years—and
their offspring have a pretty high
survival rate.
But they have quite a few factors
working against them. For one thing,
they are really cute. Their tiny size—
just about four inches long when
fully grown—make them targets
for poachers who sell them on the
black market.
The turtles are also rather particu-
lar about their habitat. They thrive in
fens, a type of wetland habitat sim-
ilar to marshes and bogs but with a
fresh water source like underground
springs. They need an open canopy
so they can sun themselves, tussock
sedge mounds on which to lay their
eggs, and plenty of muck in which
to hunker down to escape predators
and hibernate in winter.
Scientists believe that bog turtles
were once widespread. About
10,000 years ago, the ice sheets that
covered North America began to
melt, forming lots of soggy fens that
were ideal habitat for the tiny turtles.
But as the continent dried out and
temperatures continued to rise, fens
became fewer and farther between.
The bog turtles that survived are
now found in small, isolated groups
separated by many miles—a chal-
lenge for a species not known for its
inclination or ability to travel distanc-
es. In fact, there are only about 500
groups of bog turtles remaining in our
region. And some of these population
pockets consist of a single turtle.
What’s more, these isolated habi-
tats are being degraded by trees that
block sunlight and invasive plants
that grow quickly from fertilizer
runoff, and destroyed by encroach-
ing development.
“Bog turtle wetlands have been
obliterated by development, ditched,
poisoned, and surrounded by roads
and houses for centuries,” said Lori
Erb, turtle conservation biologist
with the Mid-Atlantic Center for
Herpetology and Conservation
(MACHAC).
Given all of this, the future for bog
turtles might look decidedly grim.
But a recent study suggests that
the species could persist for at least
another century.
Researchers tracked several
upstate New York populations of
bog turtles for almost a decade.
They found that, on average, female
turtles produced nearly one baby a
year, and these offspring had a 33
percent chance of surviving their
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