UA red squirrel estimates skewed

A critical point has arrived in the 10-year effort by the University of Arizona to escape environmental laws and court injunctions and construct a complex of telescopes on Mt. Graham. Rep. Jim Kolbe is seeking to sneak through a second exemption to the Endangered Species Act in a "rider" on an unrelated bill, as a special favor to the UA. One may ask "who's next?"

The project is in the heart of a small patch of forest which is the primary habitat of the Mt. Graham Red Squirrel, which is endangered. The squirrels eat berries, fungi, truffles and conifer seeds, which are stored in piles called "middens" for food security.

A monitoring program for the squirrel has been conducted by the UA since 1989, the results of which will be critical to efforts to build four more telescopes in this area. The UA will attempt to show either evidence of no impact, or more perversely, improvement in squirrel populations. Just such a claim surfaced in a recent pro-telescope letter to the Wildcat.

The UA monitoring program covers three areas. From east to west, the first is 317 acres of forest around High Peak and Hawk Peak, the easternmost of the high peaks; the second is an area of 225 acres around Emerald Peak; and the third is an adjoining 290 acre area. Arizona Game and Fish and federal agencies do less-detailed monitoring in all suitable habitat on the mountain. In reviewing the monitoring programs I have found the following major problems:

No direct count of squirrels. Active middens are counted as "squirrels" by observers, and observers may differ in their judgment of "active." Actual squirrel counts are problematic, as squirrels spend over 85 percent of their time out of sight of middens. Additional unknowns are the extent of use of a midden by more than one squirrel, or of more than one midden by one squirrel, and how such patterns of use might vary through the year. Tagging of squirrels results in deaths.

No before/after comparison for telescopes. The pre-construction count was only for one year, 1989, and this took place after cutting of trees and is an underestimate of real numbers, since discovery of new middens increased markedly after the first survey. The monitoring program refers to the High Peak zone as a "control," against which numbers in the telescope zone are compared. This is not valid, as similarity of the two forest areas is assumed, not shown. The possible effects of telescopes go beyond the loss of food trees in the building and road sites. There will also be increased year-round activity, not the least of which is the presence of "security" dogs at the telescope site! There may also be "edge effects" of buildings, roads and clearings, which have yet to be adequately studied. The increase in warmer, drier edge areas may result in disproportionate reductions in mushroom crops and suitable midden sites and increases in predation or wildlife risk. Thus, long-term changes resulting from telescope construction cannot be estimated from the UA monitoring program data.

Total population and habitat are too small. In the 830 acres monitored by the UA, early summer active midden counts range from 25 in poor years to 80 after exceptional cone crops. U.S. Fish and Wildlife estimates less than 2,000 acres of "good/excellent" habitat remain. Arizona Game and Fish have estimated total active middens between 146 and 370 (with all the problems of estimating squirrel numbers mentioned above). In addition, these estimates may be inflated by failure to re-examine and exclude once-active, now abandoned middens. The numbers are very small, which is why the squirrel is listed as endangered.

Extinction risk has been estimated at 30-70 percent in the next 30 years. The Forest Service developed a model for extinction risk with some methodological problems and drastic conclusions. It was included in the final environmental impact statement but largely ignored, and no new estimates have been done. Extinction remains highly plausible with any unusual run of dry years, consequent wildfires and low food production all probably aggravated by forest fragmentation. An influence of global warming is likely to be significant here, but has not been investigated. Minimum viable population of 300 adults as specified in the Recovery Plan has not been attained in four of six yearly population estimates. Every species has a "minimum viable habitat" size. Populations can persist in the short term, but still be doomed to extinction in 50-100 years by the reduction of habitat below what is necessary to maintain a viable population.

The General Accounting Office maintains that no adequate biological assessment has yet been done for the risk of the project to the squirrel. Population estimates are biased and extinction risk assessment inadequate. Despite populations below an estimated viable minimum, which should require a freeze on all habitat destruction, the UA has cleared more trees and will clear more if Kolbe's rider goes through. Other issues should be remembered. The squirrel is just one of several rare species which could be affected by activity on the mountain. The San Carlos Apache tribe has repeatedly stated that the mountain is sacred to them. It is valuable to the many recreational visitors every year. This is an additional threat, but also a demonstration that a large portion of the community would prefer to experience intact forest and the life it protects than to stare at a barren telescope complex.

Martin Taylor is an assistant professor in the Department of Entomology and a population and environmental biologist.

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