Description
The Northern Water Snake is red to brown with
alternating dark blotches on the back and sides at the midbody.
Older snakes are darker, eventually becoming almost black. The
belly is lighter in colour, often white or yellow with
dark crescent shaped spots on it. The Lake Erie Water Snake is a
subspecies of Northern Water Snake which is only found on islands
and the southern shore of Lake Erie. It is uniformly gray above
rather than banded or blotched.
Confusing Species
There are a number of other boldly blotched snakes in
eastern Canada. The Northern Water Snake may be confused with the
Fox Snake (which has a yellowy
background
colour), Milk Snake (which has
a Y- or
V-shaped blotch on the back of its head) or the Eastern Hognose Snake (which has
an upturned
snout). Darker individuals can be confused with the rare Black Rat Snake, which is jet black
in
colour.
Distribution
In Canada, the Northern Water Snake is limited to
southern Ontario, south of Lake Superior, and extreme southern
Quebec. In the US, it is found as far south as Louisiana and as
far west as Oklahoma.
Habitat
The Northern Water Snake can be found in almost any
permanent body of freshwater within its range, although the
preferred habitat is clear, running streams. They are rarely found
more than a few metres from water.
Reproduction
Breeding occurs in the spring after emerging from
hibernation. Aggregations of up to 12 males and one female have
been reported. Females develop the eggs within their bodies and
give birth in later summer or early autumn. In Ontario, females
give birth to an average of 23 young. A given clutch of hatchlings
often has more than one father. Hatchling size is related to the
mother's size, but averages about 18 cm. In Canada, it takes 3-4
years to reach maturity at a size of 50-60 cm. As in many species,
young adults may not breed annually.
Natural history
The Northern Water Snake is often found hunting for
prey along the water's edge or underwater. It is an excellent
swimmer and can be found up to 3 m below the surface of the water
and several kilometres from shore. It commonly eats fish and
amphibians. Although small prey are usually swallowed head first
upon capture, large fish may be carried to shore before being
eaten. The Northern Water Snake frequently basks in the open,
often in large groups. If captured, it will bite and the wound
will generally bleed profusely, because although not poisonous, the
saliva contains an anticoagulant. The Northern Water Snake
hibernates in groups, sometimes even with other species, in a
variety of different sites including burrows, hollow logs, rock
piles or muskrat dens.
Conservation Concerns
The Northern Water Snake is widespread and abundant in
Canada and is one of the most commonly seen snakes around lakes.
The Lake Erie Water Snake, a subspecies found only on islands in
the western end of Lake Erie and part of Ohio is Endangered,
largely due to persecution by humans.
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