Presence and habitat use of bats in the White Mountain National Forest

Little is known of the presence and habitat use of bats in the White Mountain National Forest, NH. Knowledge of their distribution and ecology is necessary to understand how timber management techniques affect bats. Of the nine species of bats found historically in New Hampshire, one is listed as endangered and three as species of concern. Bat detectors (Anabat, Titley Electronics, Australia) were used to survey the relative abundance and feeding activity of bat species at two foliage heights in four age-classes of northern hardwood and spruce/fir forest stands. The effect of elevation on relative species presence, the association of bats with trails and water bodies, and the presence of flying insects in each forest type was also investigated. Mist nets and a harp trap were used to complement the detector surveys. The calls of captured bats were recorded to develop species-specific echolocation signatures appropriate to the Anabat system. Initial data indicate that bat activity was highest in over-mature hardwood stands (36%) and group cuts in spruce/fir (30%), whilst activity was similar in all other forest types (x̄ = 12%). Within a forest stand activity was uniform, except at trail and water body edges where it was three times greater. Of the five species of bats trapped, 77% of individuals were Myotis lucifugus. Only adult males were captured prior to 25 July 1992; the subsequent capture-rate of sexes was equal (37% juvenile).