Saturday, February 9, 2013

Help For the Mount Graham Red Squirrel?

The Mount Graham red squirrel has been listed as an endangered species since 1987, after having previously been thought extinct. It lives a precarious existence in a small area of Arizona, where it numbers only slightly above 200 individuals. Now it appears that a long-planned captive breeding program at the Phoenix Zoo may finally be nearing approval from the US Fish and Wildlife Service.

This small subspecies of the North American red squirrel lives in high-elevations conifer forests in the Pinaleno Mountains of Arizona, where it has been isolated from other red squirrels for over ten thousand years. Its numbers have declined due to habitat loss, drought and forest fires. In the 1990s this squirrel became controversial when conservation groups objected to the construction of a University of Arizona observatory in its territory, and since the construction the numbers of squirrels have been closely monitored.

The Phoenix Zoo captured four of the squirrels, two males and two females, in 2011 when it feared that wildfires that summer might devastate the remaining population. The two females died, but the males remain in captivity at the zoo. Zoo researchers have been learning everything that they can about these squirrels in the hopes of starting a captive breeding program to replenish the numbers, which are currently so low that the species could be exterminated by a single ecological disaster such as a forest fire or severe drought.

One of the captive male Mount Graham red squirrels

There are difficulties with any effort to breed Mount Graham red squirrels in captivity. The squirrels are extremely territorial, and will not tolerate the presence of other squirrels in their vicinity except for mating. The females of the species go into heat for only one day a year, so the timing has to be perfect. The zoo researchers are developing a guide for keeping the squirrels in captivity, which is being updated as they learn more.

The proposed pilot program calls for capturing a maximum of sixteen Mount Graham red squirrels over a period of ten years for captive breeding. After that ten years, a decision would be made based on results, on whether to launch a full breeding program. The Fish and Wildlife Service may approve the pilot program as early as this spring, although further delays are also possible.

The real question, of course, is whether the species can survive long enough to see the implementation of the program.

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