Habitat use by spotted bats ( Euderma maculatum, Chiroptera; Vespertilionidae): roosting and foraging behaviour.

In the Okanagan Valley, southern British Columbia, spotted bats concentrated their foraging activity in open areas adjacent to ponderosa pine Pinus ponderosa. None of the over 1000 attempted captures of prey witnessed involved bats gleaning insects dives to the ground or foliage. Some attacks on flying insects involve steep dives to the ground, presumably in response to the defensive behaviour of prey. Spotted bats foraged alone, avoiding one another apparently by listening to the echolocation calls of conspecifics. Intrusion by one bat into the feeding area of another resulted in an altercation which stopped when one bat left the area. Heavy rain may have inhibited foraging flights, but there was no evidence that other meteorological factors or moonlight significantly inhibited foraging activity. The bats roosted alone in steep cliff faces; 2 radio-tagged individuals returned consistently to the same cliff face to roost. Departure was presumably influenced by light levels, bats departing on cloudy nights than on bright ones. -from Authors