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Snapping Turtle
Chelydra serpentina
by Jeff
LeClere
Status
Snapping turtles are listed as a Species
of Special Concern in Minnesota due to harvesting procedures.
Although a license is required, harvesting is largely unregulated.
Description
This is Minnesotas largest turtle species.
Average adult size is from 9 to 14 inches carapace length.
The largest Minnesota specimen recorded was a male that measured
19 1/2 inches (Gerholdt and Oldfield, 1987)! The turtle (dubbed
Minnesota Fats) was tagged and released after his Minnesota
State Fair appearance.
Unlike most of Minnesotas aquatic turtle
species, male snapping turtles grow larger than females. The
males also have their cloacal openings positioned past the
margin of their carapace edge. The strong, well developed
carapace is brown, olive gray or black, but may be obscured
by mud or algae.There are three lengthwise keels down the
carapace. These are prominent in young specimens, but are
obscure or absent in adults. The marginals are smooth on all
sides except the rear in which they become like jagged teeth
in feeling and appearance. The plastron is small resulting
in a large amount of flesh exposed on the underside.
Snapping turtles may be quite variable
when it comes to skin coloration, especially in immature turtles.
They may be light brown to almost yellow , rusty orange, or
reddish. The throat, limbs and ventral surface (including
tail) are where this coloration is richest. These colors may
be an enhancement due to diet, water quality, or soil type.
However, adults found in the same body of water rarely exhibit
these colors. Adults are usually brown, gray, or nearly black.
Neonate snapping turtles are very dark with some white flecking.
Young snapping turtles usually have chestnut brown shells
with lighter lines radiating from the centers of each scute.
All ages have strong jaws with a hooked beak, strong claws,
and a long saw-toothed tail.
Subspecies
The subspecies found in Minnesota is the
common snapping turtle, Chelydra serpentina serpentina.
Range
Statewide.
Habitat
The snapping turtle is found wherever
permanent water exists. Lakes, ponds, rivers, streams, marshes,
and water-filled ditches are used.
Habits
Snapping turtles (often referred to as
snappers) are well-known for their extremely aggressive behavior.
Their strong jaws are capable of giving a serious, painful
bite, although the resulting damage is sometimes exaggerated.
While very pugnacious on land, they usually try to crawl or
swim away if they are confronted underwater.
This is one of Minnesotas most aquatic
turtle species. They only occasionally bask out of water,
most specimens are seen in spring. They bury themselves in
the mud at the bottom of shallow waters with only their head
protruding. With their long necks, they occasionally reach
the waters surface and take in air through their nostrils.
In the evening and at night they become active and hunt for
food.
I have observed an adult snapper foraging
in Houston County, MN. It moved rather quickly along the bottom
and probed every burrow or sunken object with its snout for
food. It did not seem to search these area with its eyesight.
It appeared to rely upon olfactory cues to determine if there
was food present.
During periods of dry weather, snappers
may move overland to search for new homes. It is very common
to see females moving (especially across roads) during the
egg laying season in June. Females normally select sandy areas
to dig nests. Riverbanks, shoulders of roads, driveways, and
lawns are common sites. Females lay up to 30 eggs and covers
the nest with soil when finished. The females then returns
to her home. Nearly all the nests are destroyed by predators.
The eggs hatch in about 50 to 60 days. Temperature during
incubation determines the sex of the hatchling turtles. Lower
temperatures produce mainly males and higher temperatures
produce mainly females.
The young turtles are very vulnerable
during their first few years of life. Most do not become very
aggressive until they are over four inches carapace length.
Snapping turtles become active in April, and overwinter starting
in October. Snapping turtles can be seen hibernating beneath
the ice on some clear lakes. The turtles may move a little
during this period, but they generally do not eat. Snappers
living in shallow bodies of water bury themselves in mud to
avoid freezing.
Food
Snapping turtles are omnivorous. They
eat anything they can catch and also various water plants.
Small prey are swallowed whole; larger items are torn apar
twith the front claws and swallowed in pieces. Although there
are reports of snappers consuming waterfowl, they do not pose
a threat to game species-including fish. Snappers are usually
too slow to catch healthy game fish. Sick or dead fish are
primarily consumed. Like many other Minnesota turtles, snappers
must eat most food underwater; their fixed tongue makes it
very difficult to swallow out of water.
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