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Canadian Amphibian and Reptile Conservation Network - Réseau Canadien de 
Conservation des Amphibiens et des Reptiles

Heterodon platirhinos
Eastern Hog-nosed Snake / Couleuvre à Nez Plat


Eastern Hog-nosed Snake

The Hog-nosed Snakes, and other roboust, rear-fanged snakes, which were included within the Family Colubridae, have recently been placed in the Family Xenodontiidae.

Description
Most individuals are yellow or light brown with large dark blotches. Some snakes are completely black. The underside of the tail is noticably lighter in colour than the belly. The body is thick and the neck is wide compared to other species. The Eastern Hog-nosed is so-named because of its slightly upturned snout. The scales are keeled. It can grow to just over a meter in total length.

Confusing Species
There are a number of other boldly blotched snakes in eastern Canada, notably the Northern Water Snake, Milksnake and the Foxsnake. None of these snakes have the upturned snout. The Western Hog-nosed is similar but is only found on the prairies in Canada. It has dark blotches on the underside and the snout is more sharply upturned.

Distribution
The Eastern Hog-nosed Snake is limited to southern Ontario in Canada. In the US, it is found as far south as Florida and Texas.

Habitat
The Eastern Hog-nosed Snake is found in sandy habitats, particularly near the shorelines of the Great Lakes. It can occur in open woodlands, particularly oak or pine, but rarely far from water.

Reproduction
Mating generally occurs in the spring. Females lay an average of 20 eggs (up to 61) in June or July. The eggs are laid in sandy soil, under rocks, or even in rotting logs. They hatch in about two months and the young are approximately 20 cm in length. Eastern Hog-nosed Snakes mature after their second winter.

Natural History
The Eastern Hog-nosed Snake has a very mild venom which may help to immobilize the toads and frogs it feeds upon. When disturbed it will raise its head, spread its neck like a cobra, hiss and even strike, although generally with the mouth closed. If it is disturbed again it may play dead by rolling onto its back with its mouth wide open and tongue hanging out. This behaviour might deter some predators who only eat living prey. The snake is not immobile at this point because if it is turned over onto its belly it will flip over onto its back again. Hog-nosed Snakes generally hibernate alone underground or in logs. The upturned snout is used for digging. Individuals can live up to 7 years in the wild.

Conservation Concerns
The sandy, open habitat of the Hog-nosed Snakes around the Great Lakes is threatened by development. Traffic mortality is another major threat to this species. In addition, this snake is commonly killed by people because of its defensive behaviour. As a result of these threats, the Eastern Hog-nosed Snake has been designated Threatened in Canada by the COSEWIC.