Species Assessment for the Midget Faded Rattlesnake (Crotalus viridis concolor) in Wyoming
Gary P Beauvais
Tags: WLCI Agency Report
The midget faded rattlesnake (Crotalus viridis concolor) has long been considered a subspecies of the western rattlesnake (C. viridis). This document will follow this convention, although there is some discussion of taxonomic revision at the species level that would categorize the midget faded rattlesnake as C. oreganos concolor (Crother et al. 2003). Midget faded rattlesnakes are a pale brownish gray, cream, or straw color. Blotches on the body are faded, subrectangular or sub-elliptical. As with most rattlesnakes, the most distinguishing feature is the rattle. Midget faded rattlesnakes are pit vipers, with the typical heat-sensing pits on each side of the head, between the eyes and mouth, used for detecting prey.
The midget faded rattlesnake mainly occupies the Colorado Plateau of eastern Utah, western Colorado, and southwestern Wyoming. Midget faded rattlesnakes are shy and inhabit rocky and arid basins. Exposed rock outcrops and ledges are important habitat features because they provide safe hibernacula, escape cover, and thermal cover.
While not listed as Threatened or Endangered by the U.S. Fish and Wildlife Service (USFWS), “take” of the midget faded rattlesnake is restricted in Wyoming by the Wyoming Game and Fish Department (WGFD). Although reliable population estimates have not been established, it is generally considered to be a rare taxon in Wyoming and across its range.