DO TURTLES COPE WITH WINTER?
the coming of winter, temperature is the most obvious environmental
factor influencing the lives of plants and animals. Many mammals add
a layer of body fat when Jack Frost arrives. Migratory birds fly south
as cold weather approaches. Deciduous trees lose their leaves. Following
are questions I have received about how turtles survive the cold.
I live in central Alabama and realize that many reptiles hibernate underground
during cold weather. But where do the turtles go that I saw on logs
in the river a few weeks ago? Can they live all winter beneath the water
or do they hibernate on land?
For most reptiles, including turtles, when their body temperatures reach
40 to 50 degrees F, they become sluggish, stop eating and seek hiding
places to get safely through the winter. Many aquatic turtles go into
the bottom mud or under the bank where the water is cold but does not
freeze. An advantage reptiles have over most birds and mammals is that
their metabolism drops with their body temperature, which means they
require less oxygen. Some turtles can stay below the water for days
at a time, as long as the water stays cold.
turtles are capable of underwater respiration through special capillaries
that allow them to release carbon dioxide while acquiring oxygen from
the water itself. Others sit quietly on the bottom, rising to the surface
periodically to take a breath. I once caught a large snapping turtle
in Michigan that poked its head up through a hole in the ice of a lake,
took a breath and then proceeded to head back to the bottom. It was
moving so slowly that I reached out of the boat and picked it up with
Last week I found six newly hatched slider turtles that I have kept
inside in a small aquarium. I read that baby sliders and painted turtles
usually stay in their nest until spring but sometimes hatch out in the
fall like these did. My question is this: Should we return the hatchlings
to the pond to live out the winter or do they have a better chance of
survival in the aquarium until spring? I assume they would survive just
fine in our large pond but thought Id check with an expert.
As far as winter weather goes, the hatchling turtles will be OK if you
put them in the pond. They will find places to hibernate when the water
begins to turn cold and will emerge in springtime to start feeding.
The threat of predators, however, exists whether you release them now
or wait till spring. Placing them in an area with heavy aquatic vegetation
would confer a slight advantage as it would provide cover that might
allow them to avoid some predators.
I read that turtles lay eggs in spring, but, even though the babies
may hatch during summer, they might not leave their underground nest
for a year or more. Is this true?
Yes. Most turtles lay their eggs on land in spring or early summer,
and most eggs hatch in late summer or autumn. In many species the hatchlings
do not leave the nest until the following spring, often a year or more
after the eggs are laid. This phenomenon, known as overwintering in
the nest, occurs worldwide among many different kinds of turtles.
underwater is not particularly unusual for a reptile. That some hatchlings
spend the winter on land in the nest, however, demonstrates, once again,
the versatility and intricacy of our native wildlife. This winter, if
you take a walk around a lake or pond, adult turtles will be lying dormant
in the water whereas baby turtles will be hidden away on land. Although
scientists learn more each year about how plants and animals survive
in the natural world, many questions remain to be answered about even
the most common species.
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