Roost selection by male and female northern long-eared bats in a pine-dominated landscape

We radiotracked 17 male northern long-eared bats (Myotis septentrionalis) to 43-day roosts and 23 females to 49-day roosts in the Ouachita Mountains of central Arkansas during summers 2000–2005. We compared characteristics of roost trees between males and females, and compared characteristics of sites surrounding roosts with random locations for each sex. Roosts were located in cavities, crevices, and under loose bark, primarily in snags; 85% of male and 95% of female roosts were in snags. Shortleaf pine (Pinus echinata) was the most utilized tree species (71% of roosts) and both sexes preferred (P < 0.05) pine snags over hardwood snags. Most (80%) snag roosts were in snags 10–24.9 cm dbh, but females roosted in snags of greater diameter than males and males tended to roost more in small (<10 cm dbh) hardwoods than females. Female roost sites were more likely to have fewer large (≥25 cm dbh) hardwoods, fewer midstory pines 5–9.9 cm dbh, fewer small (<10 cm dbh) hardwood snags, more overstory pines ≥25 cm dbh, and more pine snags <10 cm dbh than random sites. Most (55%) female roosts were located in pine-dominated stands that had undergone partial harvesting and midstory removal. Males were more likely to select sites with abundant large (≥25 cm dbh) overstory pines, fewer small overstory pines (10–24.9 cm dbh), and more large pine snags ≥10 cm dbh than random. More male roosts (42%) were in unharvested stands than female roosts (24%), and females roosted at sites with fewer midstory trees than males. Our results demonstrate the importance of pine snags as roosting habitat for northern long-eared bats and the importance to females of snags located in relatively open forests in the Ouachita Mountains during summer.