Eastern Hognose Snake (Heterodon platirhinos)

Description:    The Eastern Hognose is a small to medium-sized snake, typically ranging 2-3 ft (0.6-0.9 m) but occasionally exceeding 4 ft (1.2 m). It is most recognizable by its upturned, keeled rostral scale (at the tip of the snout) that gives it the “hognose” name. Coloration is extremely variable in Eastern Hognose, with juveniles usually patterned with dark brown, black, or reddish blotches on a tan, gray, yellow, blueish, or reddish body. In this region, many adults are patternless, appearing solid black or gray, while others may retain patterning. This variability can cause confusion with other snakes, including venomous species such as Copperheads or Pygmy Rattlesnakes. However, the identifying “hog – nose” allows for easy identification. Scales are heavily keeled, giving a rougher texture, and the anal plate is divided. Eastern Hognose can also be confused with the much rarer Southern Hognose (Heterodon simus), but can be differentiated by its less “steep” or pronounced rostral scale and by the underside of its tail, which is typically lighter than the belly.

Range and Habitat:    The species ranges widely across the eastern and central United States, from southern New England and the Great Lakes region south to Florida and west to Minnesota, Texas, and extreme eastern Colorado. In the Southeast, they can be found throughout the Coastal Plain, Piedmont, and lower Appalachians.

Eastern Hognose shows strong associations with xeric habitats, especially those with well-drained sandy soils. They show selection for open, sandy habitats with early-successional forest patches containing woody debris and low ground cover, which are often used for nesting. In Georgia and South Carolina, they are strongly associated with longleaf pine habitat, dry oak hickory forests, coastal dune systems, and fields with nearby wetlands that support amphibian prey.

Habits:    Eastern Hognose Snakes are diurnal (active during the day) and have surface activity strongly tied to temperature and humidity. They are most active when temperatures are moderate and humidity is high. Gravid females tend to spend more time on the surface than males, and overall activity peaks during spring and fall, with the highest levels occurring from September through October.

Eastern Hognose Snakes are dietary specialists that feed primarily on toads (Anaxyrus spp.), often consuming them in large numbers. They possess enlarged rear maxillary teeth that are used to “pop” inflated toads (a common defense strategy for toads) and produce mild venom through Duvernoy’s gland secretions that aid in subduing prey and counteracting the bufotoxins secreted by toads. These adaptations likely reduce prey struggling during ingestion and minimize the risk of injury to the snake’s delicate skull and jaws. In humans, bites may occasionally cause mild localized effects such as swelling or irritation, but are not medically significant. Although toads dominate their diet, hognose snakes will also opportunistically take other amphibians (frogs, salamanders) and, less frequently, small mammals or invertebrates.

Hognoses are also well known for their dramatic defensive displays. When threatened, they flatten their necks (like a cobra), hiss loudly, and may deliver bluff strikes to scare away the threat without biting. If harassment continues, they often roll onto their backs, smear themselves with foul-smelling musk, and feign death; a behavior known as thanatosis. In some cases, they rupture small blood vessels in the mouth, causing bleeding from the oral cavity and even the cloaca to enhance the illusion of mortality. The adaptive value of this strategy remains highly speculative, but one hypothesis is that the musk contains chemical traces from their toxic toad prey. For predators with a strong sense of smell, the combination of a seemingly dying animal and the odor of toxins likely signals an unsafe or unpalatable meal.

Breeding occurs in spring, with eggs being laid from early to midsummer. Females deposit 4-50 eggs (commonly 15-25) in sandy soils, under logs, or in mammal burrows in June and July. Incubation lasts ~2 months, with hatchlings emerging in late summer at 6-9 in (15-23 cm). Reproductive success depends on access to sandy nesting habitats, which females actively select within their home ranges.

Eastern Hognose also have relatively small home ranges (often <20 ha), but movements are constrained by habitat fragmentation and roads. For example, studies show that hognoses try to avoid crossing paved roads. However, they frequently cross unpaved roads, which may limit gene flow and contribute to local population isolation.

Hognose snakes are mid-level predators and, because of their toad-specialist diet, play an important role in regulating amphibian populations. They themselves are preyed upon by raptors, wild turkeys, coyotes, raccoons, feral cats, and larger snakes. However, their cryptic coloration and dramatic displays reduce predation risk.

Conservation Status:    The Eastern Hognose Snake is listed as a species of Least Concern globally but is considered threatened or of special concern in several states and in Canada due to habitat loss, road mortality, the pet trade, feral cats, habitat alteration, and human persecution. Habitat fragmentation, especially loss of sandy barrens and coastal dune systems, poses major conservation concerns. They are protected in the states of Georgia and South Carolina.

Pertinent References

• Buchanan, S.W., B.C. Timm, R.P. Cook, R. Couse, & L.C. Hazard. 2016. Surface activity and body temperature of Eastern Hognose Snakes (Heterodon platirhinos) at Cape Cod National Seashore, Massachusetts, USA. Journal of Herpetology 50:17-25.
• Robson, L.E., & G. Blouin-Demers. 2013. Eastern Hognose Snakes (Heterodon platirhinos) avoid crossing paved roads, but not unpaved roads. Copeia 2013(3):507-511
• Taub, A.M. 1967. Comparative histological studies on Duvernoy’s gland of colubrid snakes. Journal of Morphology 121: 233-258.
• Buchanan, S.W., et al. 2017. Spatial ecology and habitat selection of Eastern Hognose Snakes. Journal of Wildlife Management 81:509-520.
• Robson, L.E. 2011. The spatial ecology of Eastern Hognose Snakes (Heterodon platirhinos): habitat selection, home range size, and the effect of roads on movement patterns. M.Sc. Thesis, University of Ottawa