The potential for vocal signatures in the calls of young hoary bats (Lasiurus cinereus)

Abstract

We examined calls produced by the solitary bat Lasiurus cinereus during mother–young interactions and considered the potential for vocal signatures in the calls of the young. Families of bats were observed in the field at Delta Marsh, Manitoba, and vocalizations were recorded using high-speed ultrasonic recording equipment. Adult female bats and young vocalize primarily during reunions. Variation in duration and maximum and minimum frequency of the calls of young was calculated. The degree of call variation within L. cinereus family units was relatively high and calls produced by different young could not be differentiated. These observations suggest that a vocal signature, which is present in some colonial species of bats such as Myotis lucifugus and which allows auditory discrimination between calling young, is less likely to occur in L. cinereus.