We used radiotelemetry to locate 59 roosts of long-legged myotis (Myotis volans) and other bat species at Mt. Trumbull in northwestern Arizona from May - August, 1997 - 1999. Of the 59 roosts located, 55 were found in ponderosa pine (Pinus ponderosa) snags. At least 15 of the radio-telemeter 4 bats used more than one roost. Length of stay at a roost ranged from one to five days (x= 1.99 days). At least five of the tagged bats foraged more than 10 km from their day roosts. Roost snags were taller, found on shallower slopes, and were located closer to drainages than randomly selected snags that were not active roosts. Over 80% of the roost snags had loose, exfoliating bark. The forest surrounding roost snags was more open than randomly selected snags and had higher densities of larger diameter class trees and snags. Roost snags were more common in areas with evidence of recent fire. We used these habitat characteristics to develop a logistic regression model that correctly classified 79.2% of the roosts and 80.3% of the random snags. Nine of 12 habitat variables in our model support the theory that bats gain energetic benefits from selecting roosts in structures that receive high levels of solar radiation. Our study suggests that forest management practices that promote retention of old growth in open stands should increase available roosting habitat. We recommend leaving large diameter trees in open park-like areas, retaining snags, restoring a quasi-natural regime of low intensity fires to mimic natural processes, and to maintain these conditions in the long term.
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