A study of the influence of environmental factors on the nightly emergence of the Little Brown Bat, Myotis lucifugus while noting clustering patterns.

Abstract

We observed the effects of the abiotic factors temperature, light intensity, humidity, wind and time of sunset on the time of first nightly emergence grouping patterns and their relation to emergence time. Three roosts were observed for a week, nightly from 8:45pm to 10:15pm. Measurements of the environmental factors in question were taken at set time intervals throughout the night and at the time of first emergence. The time of first emergence differed significantly between roosts, as did the light levels at emergence. There was no significant correlation between time of first emergence and any of the abiotic variables except time to sunset. We also found that bats tend emerge in clusters, and that these group emergences were more frequent before light intensity reached 0 lux.