Selection of Day Roosts by Female Long-Legged Myotis in the Central Oregon Cascade Range

Abstract

We radiotracked 16 female long-legged myotis (Myotis volans) in the central Oregon Cascade Range that used a total of 41 day roosts. Large Douglas-fir (Pseudotsuga menziesii) snags averaging 97 ± 7 (SE) cm diameter at breast height (dbh) and 38 ± 3 m in height were the most commonly used roost structures (88%). The odds that a snag was used as a day roost increased as snag height increased (P < 0.001); after snag height was accounted for, the odds of use decreased as stand height within 20 m of the snag increased (P = 0.024). The frequency of occurrence of roosts between young and late seral stands did not differ from that by chance in these 2 stand conditions (P = 0.76). Day roosts generally occurred in upland habitats associated with streams that contained night roosts. Management of large diameter, tall snags that extend above the canopy will provide 1 component of day-roost habitat for long-legged myotis in managed landscapes.