Sonora annulata, commonly known as the Colorado Desert shovelnose snake, is a species of small, nonvenomous snake in the subfamily Colubrinae of the family Colubridae. It was first described by American naturalist Spencer Fullerton Baird in 1859 under the original name Lamprosoma annulatum.
Taxonomy and Nomenclature
The species has undergone several taxonomic revisions. It was formerly classified in the genus Chionactis (as Chionactis annulata or as a subspecies Chionactis occipitalis annulata), but more recent phylogenetic work has placed it within the genus Sonora. The specific epithet annulata is derived from Latin annulatus, meaning "ringed," in reference to the dark bands encircling the body.
Description
Sonora annulata is a small, slender snake with smooth, shiny scales. It possesses a distinctive flattened, spade-like scale on the tip of its snout (a rostral scale), which is adapted for burrowing in sandy soils. The body is typically cream or yellowish in color with alternating black and red or orange crossbands that encircle the body. Adults generally reach a total length of 11 to 17 inches (28–43 cm).
Distribution and Habitat
The species is native to the southwestern United States and adjacent northwestern Mexico. In the United States, it is found in southwestern Arizona and southeastern California. In Mexico, it occurs in northeastern Baja California. Its habitat consists of sandy desert regions, including the Colorado Desert and Sonoran Desert.
Behavior and Diet
Sonora annulata is a nocturnal, secretive, burrowing snake. It preys primarily on insects, scorpions, and small lizards.
Subspecies
Two subspecies are currently recognized:
- Sonora annulata annulata (Baird, 1859) – the nominotypical subspecies, commonly known as the Colorado Desert shovelnose snake.
- Sonora annulata klauberi Stickel, 1941 – commonly known as the Tucson shovel-nosed snake. The subspecific name honors American herpetologist Laurence Monroe Klauber.
