Crotalus oreganus abyssus


Crotalus oreganus abyssus is a venomous pit viper subspecies found only in the U.S. states of Arizona and Utah.

Description

This is a medium to large rattlesnake. Adults measure 16-54 inches in total length.
Dorsally, they have dark blotches on a variety of base colors ranging from reddish, pink, yellow/green, light tan, to gray. The blotches usually become crossbands near the tail. The young usually have more prominent blotches and facial markings than the adults. Some adults have no body markings.
The rostral scale usually comes into contact with more than 2 internasal scales.

Geographic range

Found in northwestern and north-central Arizona along both rims and the floor of the Grand Canyon and adjacent areas,, and North into Utah on the Kaiparowits Plateau between the Escalante River and Paria River Drainages of Kane and Garfield Counties, Utah.

Habitat

The snake is found in a variety of habitats, including grassland, Great Basin Desert scrubland, bottoms in the Grand Canyon, talus and cliff slopes, rolling hills and bajadas in pinion-juniper woodland, and pine forests.

Behavior

It is primarily diurnal but can be active around the clock when conditions are favorable. The cryptic coloration and calm demeanor of this subspecies often allows it to escape detection from passersby.

Feeding

It feeds on squirrels, mice, lizards, and birds.

Taxonomy notes

Some researchers list this taxon as elevated to a full species as, or as a subspecies of the Great Basin Rattlesnake as, in the Annotated Checklist of the Rattlesnakes, published in The Biology of Rattlesnakes II 2017.