Eastern Hog-nosed Snake

(Heterodon platyrhinos)

Status: Threatened (ESA 2008, COSEWIC 2021)

Table of Contents:

Species Identification
Diet
Habitat and Range
Biology and Behaviour
Similar Species
Threats/Reasons for Being Endangered
Conservation and Recovery Strategies
How You Can Help

Species Identification:

The Eastern Hog-nosed Snake is a large, thick-bodied snake with a distinctive upturned snout. They have olive or dark grey colouring and brownish blotches dorsally and laterally along the body. More uncommon colours include yellow/gold with dark blotches, or even pure black (melanistic). When threatened, the Hog-nosed Snake will flatten out their neck to a similar shape as a King Cobra. Juveniles have dark blotches on their back and smaller blotches on their sides.

Diet:

The Eastern Hog-nosed Snake feeds primarily on amphibians, more notably the American toad, and the Fowler's toad. They have also been known to opportunistically eat frogs, small mammals/rodents, birds, and even turtle eggs. Juveniles feed on smaller prey such as Spring Peepers, salamanders, and invertebrates. The Eastern Hog-nosed Snake will immobilize their prey by injecting them with a mild venom as they swallow.

Map taken from Government of Canada: https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry/cosewic-assessments-status-reports/eastern-hog-nosed-snake-2021.html

Habitat and Range:

The Eastern Hog-nosed Snake is only found in eastern North America, with only about 10% of populations residing in Canada. The Canadian population is only in southern and eastern Ontario, in the Carolinian and Great Lakes - St. Lawrence areas. The Land Between is the Eastern Hog-nosed Snake’s most northern territory. They can be found throughout this region, but not much farther north. In the United States, Eastern Hog-nosed Snake populations are all along the eastern side of the country, and can be found all the way south as far as Florida, and north up into Ontario.

Typically Hog-nosed snakes prefer habitats that have loose sandy soil like beaches, and open forest cover, although they have also been found in many other habitat types which suggests that this snake may be able to thrive in many different habitats. This may also be because they have such a large home range ( >100 hectares), and have been recorded while travelling through these different habitats, but not necessarily living in them. They typically avoid areas with dense conifer cover and human disturbances, which makes these areas less suitable for the species to thrive. Little is known about what habitat is preferred for hibernation.

Biology and Behaviour:

The Eastern Hog-nosed Snake emerges from hibernation in early spring and breeds in the spring and late summer. In either June or July, females will lay between 7 and 37 eggs, but the average is usually about 25 eggs. She creates a burrow in sandy soil or light gravel, digging up the substrate with her upturned nose. In two months the hatchlings will emerge and be about 20 cm in length. In Ontario, Eastern Hog-nosed Snakes reach maturity in 4-5 years, but they can mature earlier in warmer climates. They usually reach about seven years of age. In the fall when it starts to get cool, Eastern Hog-nosed Snakes will hibernate under the soil until early spring.

When threatened, Eastern Hog-nosed Snakes will flatten their neck and loudly inhale air in an attempt to look threatening. If the danger continues, they will occasionally bluff strike, but they will rarely bite in defense. If the threat continues, the Hog-nosed Snake’s last line of defense is to lay on their back and fake death, and they will sometimes even release their bowels or excrete blood. They have many predators including Raccoons, Opossums, Red Foxes, raptors and large predatory birds, as well as other snake species.

Similar Species:

The Eastern Hog-nosed Snake is often visually confused with the Massasauga, Eastern Foxsnake, and the Eastern Milksnake, since they all have similar blotches. However, the Eastern Hog-nosed Snake is the only snake in Ontario with an upturned snout, or the ability to flatten down to look like a cobra.

Threats/ Reasons for being at Risk:

1. Habitat loss and degradation: Habitat loss from agriculture and urban development is a major threat to the Eastern Hog-nosed Snake. Agriculture is especially a threat to the Carolinian population in southern Ontario, as wood lots are cut and small farms are expanding to keep up with large monoculture farms. Urban development is impacting all of the North American species, especially shoreline and cottage development, since this species prefers sand habitats.

2. Road mortality: Roads go hand in hand with urban development, especially that of cottages, as people head northward out of cities and build permanent or vacation homes. Road networks are ever expanding in Ontario, especially in The Land Between. Road mortality is a major issue when snakes are trying to cross the road, or see it as an ideal basking site. Many people either do not look for snakes while driving, or intentionally hit them.

3. Persecution: All snake species are commonly persecuted by people due to fear. Most snakes in Ontario are generally harmless, but people fear their bite and their quick movements. Snakes are often found in people’s backyards and gardens, and while they are beneficial since they eat many backyard pests, they often frighten people. There is a great deal of misinformation when it comes to snake species, and most people would rather get rid of them than learn more about them.

4. Illegal collection: Snakes are often collected from the wild to be sold into the pet trade, or picked up by people who live nearby and given as a pet. Some snakes are also killed for their skin, or for medicinal purposes. Contrary to popular belief, poaching is common in Ontario and a huge threat to most reptile species. If you take a picture of a Species At Risk, remember not to post it on social media or give away any location data, as poachers will use this information.

5. Environmental contaminants: Pollution from garbage, fertilizers, and pesticides pose a threat to the Eastern Hog-nosed Snake. Garbage is a major issue if snakes crawl through metal cans or plastic bags and get cut or stuck. Fertilizers and pesticides used in gardens or agricultural fields remain in the environment and get consumed by snakes, especially rodent poison.

Conservation and recovery strategies:

While all habitat of the Eastern Hog-nosed Snake is supposed to be protected, this only applies to crown land and government protected parks and natural areas. 38% of parks and protected areas that are supposed to be Eastern Hog-nosed Snake habitat, have not had a snake sighting since 1998. More research should go into why the Eastern Hog-nosed Snake is not in these areas today. When it comes to private land, stewardship and land acquisition policies have been put in place, but it is also crucial for the government to work with landowners to protect Eastern Hog-nosed Snakes on their property. Governments should also encourage adoption of policies by municipalities to protect significant habitat in Official plans and other planning documents (e.g. protected areas, municipalities). When it comes to road mortality, known Eastern Hog-nosed Snake areas should be signed, speed limited, and ecopassages and fencing should be put into place where high mortality occurs. Public education programs should be put into place to correctly inform the public about snakes and eliminate misinformation.

How can you help?

Landowners should keep shorelines natural, or renaturalize their shoreline. Preserve any wetland habitat whether it is significant or not to maintain the biodiversity that these snakes require to survive.
Educate landowners and neighbours about Ontario snakes and their benefits, inform them of any myths and misconceptions about snakes.
Landowners should look into safe chemical use and pollutant use around wetlands. Pick up any garbage on or around your property.
Help a snake across the road in the direction they are travelling!
Support organizations dedicated to helping snakes and other wildlife.

Additional Resources:

Ontario Nature page on the Eastern Hog-nosed Snake
COSEWIC 2021 report and assessment
Nature Conservancy Canada’s Eastern Hog-nosed Snake page

Sources:

Seburn, D. 2008. Recovery Strategy for the Eastern Hog-nosed Snake (Heterodon platirhinos) in Canada. Species at Risk Act Recovery Strategy Series. Parks Canada Agency, Ottawa. vi + 24pp.

Kraus, T. 2011. Recovery Strategy for the Eastern Hog–nosed Snake (Heterodon platirhinos) in Ontario. Ontario Recovery Strategy Series. Prepared for the Ontario Ministry of Natural Resources, Peterborough, Ontario. i + 6 pp + Appendix vi + 24 pp. Adoption of the Recovery Strategy for the Eastern Hog–nosed Snake (Heterodon platirhinos) in Canada (Seburn, 2009).