OLD DO BLANDING'S TURTLES GET?
June 23, 2013
captivating Blanding's turtles are among my favorite turtles in the
world. The species is the only native U.S. turtle found exclusively
in the northern half of the country and southern Canada--and nowhere
in the South. Their farthest excursion southward from Canada is Illinois.
turtles approach the size and shape of a football, but their allure
comes not from their physical appearance, a black shell with yellow
markings and a bright yellow chin and throat, but their personality.
The essence of their charm is their passive nature. Of the hundreds
I have seen or handled over the years when I was in Michigan, I have
seen only one bite a person, a student named Sue who poked her finger
at it. I probably should not have told her that Blanding's turtles do
not bite. But even that one didn't bite hard enough to hurt. So I still
feel comfortable saying that Blanding's turtles are extremely docile.
contemplative gaze is another intriguing trait. Big brown and yellow
eyes look right at you, unafraid yet nonthreatening. Looking into the
eyes of a Blanding's turtle makes you wonder if it feels it has chanced
upon a recent evolutionary visitor to the world but does not want to
be rude or judgmental about your presence.
Blanding's turtles are seldom seen in the wild. Finding one younger
than 10 years old is unusual, compared to the number of adults found.
The common box turtle is similar in this regard. Think how many full-grown
box turtles you have seen crossing roads or wandering through yards,
and yet how few young ones you encounter. Blanding's and box turtles
are also similar in having discernible growth rings on the shell that
can provide a fairly good estimate of their age. A new ring forms during
the cessation of growth in winter, so for the first dozen or so years,
you can count the growth rings to estimate how old the turtle is. With
Blanding's turtle over 20 years old, however, the technique is not reliable.
caught a baby Blanding's turtle in Minnesota, one of three I have seen
in the wild since I first began studying them 46 years ago. My colleague
Justin Congdon who worked with me at the Savannah River Ecology Laboratory
has seen more Blanding's turtles than I have, yet he also has caught
only a few little ones. One straightforward ecological mystery for people
who study Blanding's and box turtles: where are the young ones? They
are virtually never found with the adults.
turtles live a long, long time. I confirmed their longevity with one
I captured, or rather recaptured, in a Michigan marsh. It had been first
caught by me 33 years before. According to my earlier field notes, the
turtle was an old male when first captured in that same marsh. Blanding's
turtles take around 15 years to reach maturity, and I had judged this
one to be 25 to 30 years old when our paths first crossed. When I picked
it up more than three decades later, it had the same calm, dreamy look
of a younger Blanding's turtle, but I imagined a spark of recognition
in its eyes when it looked at me.
untimely death from automobiles, commercial turtle collectors, and the
like, an adult Blanding's turtle could be around longer than most people.
The record for the oldest U.S. turtle of known age ever found living
in the wild belongs to a Blanding's turtle--77 years old! Equally remarkable,
it was a female, and when it was found in the late 1980s it was laying
eggs. Unless it's been hit by a car, it's probably laying more eggs
time I returned the old male to the Michigan marsh, it turned its head
to look back at me. Its big brown and yellow eyes seemed to say, "I'll
be looking for you next time you visit. I'll be here." I sure hope
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