Roosting and Foraging Ecology of Forest Bats in the Southern Appalachian Mountains

Although roost sites are critically important to bats, we have few data on macrohabitat factors that affect roost selection by foliage roosting bats. Such data are needed so that forest managers can make informed decisions regarding conservation of bat roosts. Our objective was to examine roost selection by non-reproductive eastern pipistrelles (Perimyotis subflavus) and red bats (Lasiurus borealis) in a dense deciduous forest undergoing low-intensity timber management in the southern Appalachian Mountains of western North Carolina, USA. During May to August 2004-2006, we radiotracked eight red bats and seven pipistrelles to roosts for 1–14 days (red bats, 11 . 4 = x days, n = 19 roosts; pipistrelles, 7 = x days, n = 15 roosts). We compared roost and random trees or points using paired-sample t-tests for tree and microhabitat characters and logistic regression models of 1–3 variables for macrohabitat characters. Neither red bats nor pipistrelles selected roosts based on tree or microhabitat characteristics. Red bats used a wide range of stand ages and conditions and, based on our most plausible models for macrohabitat variables, roosted closer than expected ( 6 . 70 = x m) to linear openings such as gated roads. Pipistrelles only used stands ≥72 yrs in age and roosted closer than expected ( 6 . 185 = x m) to non-linear openings and at elevations lower than expected ( 882 = x m). Combined evidence of multiple variables indicated that pipistrelles preferred to roost close to streams. Our results indicate that land 2 managers in the southern Appalachians should maintain a diversity of age classes to provide roosting habitat for both species, and that pipistrelles in particular may benefit from retention of mature stands or buffer zones near perennial streams. Furthermore, nonreproductive red bats and pipistrelles may prefer to roost near openings to minimize commuting costs when openings comprise a small proportion of a densely forested landscape. Introduction Bats spend about 15 hours per day roosting, so diurnal roost habitat selection is an important component of bat ecology (Barclay and Kurta 2007). Most roost ecology studies of cavity or crevice-roosting bats have focused on characteristics of the roost tree (e.g., size, decay stage) and its immediate surroundings (e.g., abundance of suitable roosts, canopy closure; Hayes 2003, Miller et al. 2003, Kalcounis-Ruppell et al. 2005) and significant findings have often been attributed to selection for microclimate characteristics and predator avoidance (Kunz and Lumsden 2003). In contrast to cavityroosting bats, foliage-roosting bats in North America are not well-studied and microhabitat and stand-scale factors important in selection of foliage roosts are just beginning to be identified (Carter and Menzel 2007). For example, recent studies have found that foliage-roosting bats select roosts based on microhabitat characters associated with suitable microclimate (Willis and Brigham 2005) or concealment from predators (Perry and Thill 2007b). However, effective conservation of roosting habitat also requires an understanding of how foliage-roosting bats select roosts at macrohabitat (stand and landscape) scales as forest management is generally conducted at these scales.