2010 results from the U.S. Fish and Wildlife Service’s Kofa National Wildlife Refuge in southwestern Arizona identifies a population of 402 desert bighorn sheep, which is slightly less than the 2009 survey estimate of 410 sheep.

The 2010 estimate of 402 desert bighorn sheep is higher than the 2006 population estimate low of 390, however biologists say there have been no significant changes to the herd’s population over the past five years. Wildlife management agencies are concerned about bighorn sheep population estimates in the area because of the significant decline noted from the 2000 survey estimate of 812 sheep. Experts attribute the decline to drought, predators, water availability, disease, and human disturbance.