Habitat management for forest-roosting bats of North America: A critical review of habitat studies

Public and private land managers increasingly are being asked to consider habitat needs of bats (Chiroptera) when planning forest management activities. However, reliability of current data on which to base management of forest-roosting bats is uncertain. Therefore, we surveyed peer-reviewed manuscripts pertaining to habitat ecology of forest-roosting bats for the period 1980-2001. We found that there were limited data upon which to base habitat management for forest-roosting bats because relatively few studies (56 over 21 years) have been conducted, most have occurred primarily in older-aged forests with little to no active forest management, and current research has primarily focused on roost-site selection to infer habitat relationships and response to habitat change. Limited sample sizes and pseudoreplication were prevalent, and management recommendations often were made without regard to inferential bounds of collected data. We contend that studies using bat detectors have limited ability to infer habitat selection per se, and recommend that studies incorporating detectors define more appropriate objectives regarding habitat associations. The best use of bat detectors may be generation of hypotheses of habitat selection to be tested with more appropriate techniques. There also is a need to conduct more long-term, holistic, experimentally designed research, to focus habitat research on 1-2 focal species per study, and to expand habitat research to include a wider diversity of forest types and management regimes. We suggest that cooperative research efforts be developed to secure sufficient funding and logistical support for such studies. We also recommend that authors clearly state the objectives of their study, including sampling assumptions and limitations; define inferential space; ensure that results are interpreted within inferential bounds of their data, especially at the proper spatial scale; and use consistent terminology when articulating concepts and results of their work.