PHOENIX - The Arizona Game and Fish Department and the USDA Forest Service announced the results of the fall 2005 Mount Graham red squirrel survey today. Biologists estimate that a range of 276 (plus or minus 12) Mount Graham red squirrels currently occupy the Pinaleno Mountain range, also known as Mount Graham. These results are slightly higher than the fall 2004 survey results of 264 (plus or minus 12) red squirrels.
|Fall 2005 survey results of red squirrels
The Mount Graham red squirrel (Tamiasciurus hudsonicus grahamensis) is an isolated subspecies found only in the coniferous forests on the Pinaleno Mountains of southeastern Arizona. This limited distribution, combined with a small population and loss of habitat, has made the Mount Graham red squirrel vulnerable to extinction. In response to concerns about the precarious status of the Mount Graham red squirrel, the U.S. Fish and Wildlife Service listed it as an endangered species in June 1987.
Every spring and fall, biologists and volunteers from the Arizona Game and Fish Department, USDA Forest Service, U.S. Fish and Wildlife Service, and University of Arizona survey the red squirrel population.
"We actually visit randomly chosen middens, or cone scale piles," explains Tim Snow, nongame specialist for the Tucson office of the Arizona Game and Fish Department. "We look for recent activity, such as new cone scales, fresh digging and stored cones." Because red squirrels defend territories around these middens, biologists can estimate the population size from the percentage of middens showing recent activity.
Since 1991, inter-agency cooperators have conducted semiannual surveys using this methodology, once each in the spring and fall. While this spring’s results represented the lowest population estimate since 1991, this fall’s estimate remains in-line with the past five fall estimates.