As part of a conservation program for the endangered Mount Graham red squirrel, the Arizona Game and Fish Department and the U.S. Forest Service conducted an annual survey and estimated approximately 240 animals in the Pinaleño Mountains in southeastern Arizona.
The latest survey count is an increase of 26 squirrels over the 2010 estimate.
Small mammal species like the Mount Graham red squirrel typically have cyclical populations that depend on the conifer cone crop, their primary food resource. While this year’s surveys show an increase in the minimum population, biologists remain concerned about the species’ status and are exploring new ways to conserve it, including habitat improvements, squirrel research, and consideration of a pilot captive breeding program.
The red squirrel survey is conducted annually in the fall by visiting a random sample of known middens (areas where red squirrels store or cache their cones).
The Mount Graham red squirrel population spiked to around 550 animals in the late 1990s, but typically ranges between 200 and 300 individuals. Habitat losses caused by fire and insect infestations and poor cone crops caused by drought are considered primary factors in the species’ recent trends.
“Squirrel numbers are closely tied to available habitat and food resources,” says Tim Snow, nongame specialist for the Arizona Game and Fish Department. “Improving forest health and preventing catastrophic wildfire events will help ensure the continued existence of these squirrels.”
Mount Graham red squirrels live only in the upper elevation conifer forests of the Pinaleño Mountains and feed primarily on conifer seeds. Females produce two to seven young annually. The species was added to the endangered species list in 1987.
The multi-agency Mount Graham Red Squirrel Recovery Team, including the Coronado National Forest, Arizona Game and Fish, University of Arizona, Native American tribes and others, oversees conservation of the species.