Nerodia sipedon sipedon
Northern Watersnake / Couleuvre d'Eau
Click on image for video of specimens on Pelee Island
The Watersnakes, and other live-bearing, harmless snakes, which were included within the
Family Colubridae, have recently been placed in the Family Natricidae.
The Northern Watersnake (N. s. sipedon) 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 Watersnake (N. s. insularum) is a subspecies of
the Northern Watersnake which is only found on islands and the southern shore of Lake
Erie. It is uniformly gray above rather than banded or blotched.
There are a number of other boldly blotched snakes in eastern Canada. The Northern
Watersnake may be confused with the Foxsnake (which
has a yellowy background colour), Milksnake
(which has a Y- or V-shaped blotch on the back of its head) or the
Eastern Hog-nosed Snake (which has an
upturned snout). Darker individuals can be confused with the rare
Gray Ratsnake, which may be jet black in colour.
In Canada, the Northern Watersnake 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.
The Northern Watersnake 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.
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
The Northern Watersnake is often found hunting for prey along the water's edge or
underwater. It is an excellent swimmer
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
Watersnake 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 Watersnake hibernates in groups, sometimes even
with other species, in a variety of different sites including burrows, hollow logs, rock
piles or muskrat dens.
The Northern Watersnake is widespread and abundant in Canada and is one of the most
commonly seen snakes around lakes. The Lake Erie Watersnake, a subspecies found only on
islands in the western end of Lake Erie is designated Endangered by
COSEWIC, largely due to the
population's small size, habitat loss, traffic mortality and persecution by humans.