The first
time he saw them, on a freezing morning last January, George Howard thought the
odd-shaped humps protruding from his iced-over swamp were tree stumps.
But somehow
that didn't seem right. He strained his eyes. They were tree stumps with teeth?
Howard
panicked. He is, after all, the manager of the Swamp Park, which features an
alligator preserve in Ocean Isle Beach, N.C. What appeared to be the frozen
death of his alligators would be a tragedy both philosophically and
financially.
He hopped the
fence and clambered onto the pond, running toward the exposed alligator snouts.
But, what could he do? The alligators were locked in the ice and immobile.
"I was
like, holy crap, should I try to get them out of there?" Howard told The
Washington Post.
But before
he launched into an impromptu ice excavation, he decided some scientific
research was in order, or at least some hurried googling. Relief washed over
him as the search results loaded: His alligators were alive. They were
surviving in the freezing water by sticking their snouts through the ice.
Howard's worry was replaced with another emotion: astonishment.
"It was
the craziest thing I'd ever seen," he told The Post this week. "I was
just astounded. Initially I was [worried], and then I realized what they were
doing and that it was the only way they could breathe. And I thought, how
intelligent is that?"
Howard
thought it a once-in-a-lifetime alligator experience. Then, last week, a cold
snap pierced the air throughout much of North Carolina and the northeast,
freezing the water in Howard's 65-acre park near the Shallotte River.
No googling
was necessary this time. Instead, Howard posted photos straight to Facebook.
Customers were wowed. News outlets posted stories with the word
"freaky" in their headlines. The gators remained unfazed.
Every one of
the 18 alligators who live at the Swamp Park — all rescued after living in
captivity — appeared to know the cold weather drill, Howard said.
When it
starts getting cold, the alligators submerge most of their bodies in the
shallow water, then stick their noses up in the air in anticipation of the
freeze ahead, creating a little hole to breathe through.
Once the
water freezes, the ice sticks to their snouts, locking the gator-cicles in
place while their bodies dangle below the surface.
Howard
doesn't know the origin of the behavior. In fact, no one really does.
Adam E.
Rosenblatt, a biology professor at the University of North Florida who studies
how alligators respond to environmental changes, said that's the big mystery.
The
behavior, he said, is likely not something the alligators learned by practicing
but, rather, is instinctual, something developed over time through natural
selection.
"If the
alligator species has been living in cold temperatures for a long enough time,
then the ones who were able to do this are the ones that would be able to
survive and reproduce," he said.
"How
they knew how to do it? I don't think anybody knows the answer at this
point."
In the late
1970s and early 1980s, Rosenblatt said, scientists began studying the behavior
in detail. Because most alligators live in warm, southern climates — North
Carolina is about as far north as they go — it's unusual for them to even
experience extended freezing temperatures. No one except the alligators seemed
too curious about how they managed to make it through the rare freezing nights.
Then in
1983, alligator ecologists noticed an entire congregation of alligators
sticking their noses through the ice in North Carolina. They had heard
herpetological legends of outcast alligators somehow managing to survive six
straight winters in Pennsylvania or four years in Virginia.
But they
knew the ice technique couldn't be new behavior. The ancestors of alligators
evolved 245 million years ago. Surely, they didn't just choose a Keystone State
cold snap to debut a new survival technique. It turns out scientists simply
weren't paying close enough attention.
Now, they
know what's going on in the ice: When the alligators go under, Rosenblatt said,
they enter what's called "brumation" — like hibernation but for the
coldblooded — and their bodies almost entirely shut down. All they need to do
is breathe.
"They
basically shut down their metabolism. They don't need to eat because they're
not burning a lot of energy," Rosenblatt said.
"They
slow down their heart rate, their digestive system, and they just sit there and
wait out the cold weather. It's a pretty amazing adaptation."
It does not always
work. One of the earliest studies of "icing" among alligators, in
1982, examined an alligator who died doing it. After three days, its body
temperature became too low for survival.
And
scientists in 1990, for example, watched a group of alligators in South
Carolina, including baby ones and found that the baby alligators didn't know
the technique, and were seen banging their snouts on the ice trying to break
through before they drowned.
Three larger
alligators who were late to the game survived under the ice for 12 hours before
finally coming up for air and joining the others.
Once the ice
melted, they all simply retreated back to shore, basking in the sun as though
returning from a nap.
This article
was originally published by The Washington Post.
Comments
Post a Comment