Survey of Forest Bats in Managed Coniferous Forest of North-Central Idaho

Managed forests in northern Idaho are important as a significant element of the regional economy and as wildlife habitat. Timber extraction from within or near riparian forest corridors typically occurs on lands of differing ownership I stewardship that are subject to differing legislative mandates, due to incomplete knowledge of many wildlife-forest habitat relationships. Some of the legislation or policies governing forest management in the region include the Northwest Forest Plan, the Columbia River Basin Assessment, and the National Forest Management Act of 1976 (with amendments), among others. In aggregate, these laws and policies suggest that two key elements are central to preservation of the integrity offish and wildlife habitat in forests of the northwest: no-harvest buffer strips immediately adjacent to streams to protect aquatic ecosystems, and retention of snags, large-diameter live trees and downed logs for sustaining structural habitat diversity of riparian-dwelling terrestrial wildlife. Riparian habitats are of particular importance to forest bat species as foraging areas (Grindal et at. 1999). Further, dead trees (i.e., snags) of the primary tree species in the region, grand fir (Abies grandis), Douglas-fir (Pseudotsuga menziesii), western larch (Larix occidentalis), western white pine (Pinus monticola), western redcedar (Thuja plicata), western hemlock (Tsuga heterophylla), and ponderosa pine (P. ponderosa) serve as day-roosts for M volans (Baker & Lacki 2005). Thus, these non-merchantable forest components provide protection from predators (Kunz 1982, Fenton et at. 1994) and may directly influence both survival and fitness (Vonhof & Barclay 1996) because bark-roosting bats spend nearly two-thirds of their lives inside roosts. Because male and female M volans use roost snags in both lower and upslope habitats (Baker & Lacki 2005), it is likely that these and other tree-roosting bats rely on forests at the landscape scale. Given increasing pressures to provide both timber and habitat for native wildlife species, agencies and companies dedicated to ecosystem management require reliable knowledge of wildlife populations and consideration of their habitat requirements. However, few data exist for assessing forest bat community composition, structure, population status, and habitat use for any species of forest bat inhabiting north-central Idaho. A great deal of research effort has been directed toward the assessment of abandoned mines as habitat of bats in the northern Idaho (e.g., Keller 2000 & references therein), however, such reports seldom provide detailed data on the wider forest bat community. Although qualified as uncertain due to lack of available data, the state ofIdaho lists M thysanodes (fringed myotis) and M. californiclls (California myotis) as SI, or critically imperiled because of extreme rarity, and Myotis evotis (western long-eared myotis), M. volans (long-legged myotis) and M yumanensis (Yuma myotis) are S3, or rare or uncommon species (Groves et al. 1997, Idaho Conservation Data Center 2004). State listings afford these forest bats status as protected nongame species, however, in the absence of detailed forest bat community composition and day-roosting habitat data, limited measures exist to protect and maintain healthy populations of forest bats. Further, although limited data on roost-site selection exist for M volans (Ormsbee & McComb 1998), this species of forest dwelling and snag roosting bat is receiving increased research attention in the Pacific and Intermountain Northwestern U.S. The proposed study will extend ongoing research intended to fill gaps in our understanding of M volans day-roosting ecology in managed forests of the Northwestern U.S. at the tree, watershed, and landscape scales.