AARC Blog #6
Dr. Teresa Bousquet
Exotic Animal Veterinarian and AARC Board Member

Creature Feature – Western Hog-nosed Snake

Okay, so I admit that these guys are not very common in Alberta, but they are my personal favorite Alberta reptile, and SUPER cute, so I am writing about them.

There are 6 species of snakes that are native to Alberta – the Bullsnake, Plains Garter Snake, Prairie rattle snake, Red-sided garter snake, Wandering garter snake, and the Western hog-nosed snake. Western hog-nosed snakes (Heterodon nasicus nasicus) can be found in the short-grass prairie of the south-eastern corner of Alberta.

Adult Hog-nosed snakes can reach 75 cm in length, with the females typically being larger than the males. They are oviparous (laying eggs, not giving birth to live young), and can lay 4-23 eggs. They feed on toads, which they use their specially evolved shovel-like rostral scale to dig out of underground burrows.

Hog-nosed snakes are famous for their threat displays. They will hiss and flatten themselves to make themselves look larger, and will even exhibit closed-mouth strikes. If the bluff fails to deter the threat, they will fake death, flipping on their backs, gaping the mouth, hanging the tongue out, and salivate. Of course, snakes performing this behavior are deeply stressed, so please do not try to provoke this behavior if you meet one.

Interestingly, these snakes until recently were considered non-venomous. Though they still did not present a risk to humans (there has never been a reported death due to a Hog-nose bite), recent evidence shows that they are actually rear-fanged and venomous. They produce the venom (or toxin, depending on who you believe), in Duvernoy’s Gland, which is a modified salivary gland, not a venom gland as found in other better known venomous snakes. Their fangs are also not hollow, so they cannot inject the venom, and must depend on a chewing action to get the venom into the wounds cause by their teeth.

External link opens in new tab or windowhttp://www.ab-conservation.com/go/default/assets/File/Publications/Brochures/ACA_Reptiles_of_Alberta_WR_2010_v2.pdf
External link opens in new tab or windowhttp://www.biology.ualberta.ca/uploads/courses.hp/zoo301.hp/h-nasicus.html
External link opens in new tab or windowhttp://en.wikipedia.org/wiki/Heterodon_nasicus

External link opens in new tab or window