Plains Hog-Nosed Snake

Heterodon nasicus nasicus

plains_hog-nosed_snake.jpg

Image of a plains hog-nosed snake
The plains hog-nosed snake has probably been extirpated from Missouri.
Tom R. Johnson
Species of Conservation Concern
Family

Colubridae (nonvenomous snakes) in the order Squamata (lizards and snakes)

Description

The plains hog-nosed snake differs from the eastern hog-nosed snake by having a sharply upturned snout and black pigment on the underside of the tail. This species has always been quite rare in the state and has not been seen for many years; it has probably been extirpated from Missouri. Like other hog-nosed snakes, this species is known to play dead in self defense.

Similar species: The dusty hog-nosed snake (H. gloydi) lives in the sandy or loose prairie and savanna soils in southeastern Missouri — far from the loess hill prairies where the plains hog-nosed snake once occurred. The dusty hog-nosed snake has only recently been rediscovered in Missouri. It is so similar to the plains hog-nosed snake that one of the best ways to identify it is to compare geographical distribution.

Size

Length: 16 to 25 inches.

Habitat and conservation

This species is restricted to sandy, loose prairie soils; sadly, it apparently is gone from our state. The dusty hog-nosed snake, mentioned above, used to be considered a subspecies of plains hog-nosed snake. It has only recently been rediscovered in southeast Missouri, and it is critically imperiled. The nearest secure populations of both of these snakes are to the west of our state.

Foods

Toads, snakes, and lizard eggs are the primary foods, but small rodents are also eaten. The shovel-like snout is used to dig out prey items from loose, sandy soil; the prey is detected by smell.

Plains Hog-Nosed Snake dist map
Distribution in Missouri

Probably extirpated from Missouri, but we can still hope that a few may still occur in the loess hill prairies in our extreme northwestern counties.

Status

The plains hog-nosed snake is apparently extirpated from Missouri; although it was once present in our state, it has not been seen in decades and we have probably lost it. Its close relative, the dusty hog-nosed snake, is critically imperiled. Both are Species of Conservation Concern.

Human connections

Human alteration of the landscape is the underlying cause of many species’ decline. Agriculture, urban sprawl, and road building break up historically large tracts of grasslands, degrading and separating the remaining fragments, shrinking and disconnecting animal and plant populations.

Ecosystem connections

As predators, snakes contribute to the balance of nature by limiting the populations of the animals they feed upon. Meanwhile, they are preyed upon themselves by other predators: owls, hawks, crows, foxes, coyotes, and raccoons. The eggs and young are particularly vulnerable.