Distribution of breeding Arizona Grasshopper Sparrow (ammodramus savannarum ammolegus) in the southwestern United States: Past, present, and future

Publisher: USGS | Science Center: Fort Collins Science Center (FORT, Ft. Collins) | Format: URL

www.fort.usgs.gov — The Arizona Grasshopper Sparrow (Ammodramus savannarum ammolegus) breeds in desert grasslands of southeastern Arizona and southwestern New Mexico in the US, and in adjacent parts of northern Sonora and Chihuahua, Mexico. Roads that were surveyed in 1982 and 1987 in Arizona and New Mexico were relocated and roadside survey protocols were repeated More... The Arizona Grasshopper Sparrow (Ammodramus savannarum ammolegus) breeds in desert grasslands of southeastern Arizona and southwestern New Mexico in the US, and in adjacent parts of northern Sonora and Chihuahua, Mexico. Roads that were surveyed in 1982 and 1987 in Arizona and New Mexico were relocated and roadside survey protocols were repeated in 2004 and 2005 to identify changes in distribution or abundance of the subspecies during the subsequent 17 yr. The Sonoita and San Rafael valleys in Arizona and the Animas Valley in New Mexico remain as primary population centers, supporting the highest mean numbers of singing males per stop, as well as the largest populations of Arizona Grasshopper Sparrows in the US. The primary factors posing threats to the future of Arizona Grasshopper Sparrow populations appear to be loss and/or degradation of habitat due to exurban development, overgrazing, and the effects of long-term drought. Less...