Two Garter snakes listed as Threatened under the Endangered Species Act

The U.S. Fish and Wildlife Service has determined that Northern Mexican Garter snake (Thamnophis eques megalops) and Narrow-headed Garter snake (Thamnophis rufipunctatus) have warranted to be listed as “threatened” under the ESA. These two species of garter snakes are native to Arizona and New Mexico. This rule will become effective August 7, 2014.

Being listed under the ESA as “Threatened”, this species may become endangered or extinct in the near future. The best available scientific and commercial information provided has determined that interaction with nonnative bullfrogs, crayfish and predatory sport-fish are the cause for their reduction in population. Wild fires and human encroachment have decimated stream side vegetation and surface water and is another primary threat to the two species of garter snakes.

Northern Mexican Garter snake (Thamnophis eques megalops) is found in southeastern Arizona and also in isolated populations in central Arizona and South Western New Mexico. It is a fairly large gartersnake reaching 44 inches and is found the banks of streams or back water habitats.

Narrow-headed Garter snake (Thamnophis rufipunctatus) is found in isolated populations from central Arizona eastward to south-western New Mexico. Being the smaller of the two species listed and reaching a size of 34 inches, and can be found in more aquatic habitat in trout streams in higher elevations along the Mogollon Rim.

USFWS will finalize the designation of critical habitat in a future report. Both species have been protected by the State of Arizona. The State of New Mexico has Northern Mexican Garter snake (Thamnophis eques megalops) as endangered and Narrow-headed Garter snake (Thamnophis rufipunctatus) as threatened.

Written by James Tintle of Tremendous Tricolors