Some opponents like to say the telescopes will drive the squirrel extinct. According to the best scientific knowledge, that's not exactly true. What's likely is that the telescopes will reduce the squirrel's remaining habitat, increasing the chance the animals will succumb to poor cone crops, or, more likely, forest fire.
Some supporters of the telescopes like to say that the squirrel owes its best hope of survival to the telescope complex, because a mitigation plan goes along with it. Supporters - including tenured biology professors - have credited the telescope with everything from halting logging on Mount Graham to listing the red squirrel as an endangered species.
It's true that the telescope project has spurred a mitigation plan for the squirrel. But logging on Mount Graham came to a virtual standstill for economic reasons in the 1970s. And although the mitigation plan that came with Congress' sanction of the project in 1988 called for a halt to timber sales on Mount Graham, it didn't change the Forest Service's plans for the mountain, which had already been laid in 1985: "We weren't going to offer timber any more," says Rich Kvale, a district ranger with the Coronado National Forest office in nearby Safford. "We no longer had a sawmill in Safford. And there was a perception on the part of the environmental community that logging was evil."
As for the status of the squirrel, it was classified a threatened species by the Arizona Department of Fish and Game in 1976. (Interestingly, the designation allowed it to be hunted for 10 more years.) By the time the telescope proposal came along, federal biologists were already considering the squirrel for status as endangered.
"This one would have been listed regardless of whether the scopes were proposed," says Sam Spiller of the U.S. Fish and Wildlife Service in Phoenix.
One piece of information can even support opposing conclusions. Take, for example, the data on where the squirrels live. The telescope-containing spruce-fir forest on top of the mountain is relatively small (the Forest Service reports it covers about 17 percent of the squirrel's habitat) but rich in squirrels (it contains about 30 percent of the known population). So it's true that the summit forest is the richest squirrel habitat, but it's also true that the lower-lying transitional forest contains more squirrels.
Biologists, however, shy away from drawing any broad conclusions based on this information. Paul Young, the biologist who has been monitoring the squirrel populations on the mountain since 1989, says that if he had to rank the mountain's zones, the spruce-fir is probably less dependable habitat than the transitional forest right below it. "But in any given year that can turn around, because it depends on the cone crops," he says. "Which habitat is the best I don't think anyone can answer yet. No one knows how much habitat you can get rid of and know the squirrel's going to survive."