ACTIVITY PATTERNS, HABITAT USE, AND PREY SELECTION BY THE OZARK BIG-EARED BAT (PLECOTUS TOWNSENDII INGENS)
Degree: Ph.D.DegreeYear: 1991Institute: Oklahoma State UniversityAdviser: David M. Leslie, Jr.
Scope and method of study. Annual and nightly activity patterns of cave use by Ozark big-eared bats (Plecotus townsendii ingens) were monitored from sunset to sunrise approximately weekly from 25 April 1987 through 25 July 1988 by video-taping entrances of a hibernaculum and maternity cave. Foraging activities of adult females were studied by attaching radio transmitters to females during early, mid-, and late lactation in June-July, 1988, and comparisons of temporal activity and foraging area parameters were made among the three study periods. Food habits were determined by microscopic examination of fecal pellets and compared to arthropods sampled in Malaise traps.
Findings and conclusions. Nightly activity at the hibernaculum was generally limited to the first three hours after sunset...
Findings and conclusions. Nightly activity at the hibernaculum was generally limited to the first three hours after sunset. Numbers at the hibernaculum varied throughout winter because bats shifted among caves. During summer, females were active all night. Mothers foraged three times each night during early lactation and reduced the number of return visits to the maternity cave as offspring became more independent. Foraging times and distances to foraging areas increased as lactation progressed. Radio-tagged bats foraged along woodland edge associated with intermittent streams and mountain slopes.
Diet analysis revealed that lepidopterans were consumed by bats more than expected, whereas all other insects were either avoided or consumed in proportion to their availability. Size and spatial distribution of potential prey may determine food habits of bats. Lepidopterans were among the largest, soft-bodied insects available to bats and were more abundant in woodland than open habitats.
