Differentiation of Two Myotis Species (Chiroptera: Vespertilionidae) at Caves Head, Nova Scotia, Based on Echolocation Call Characteristics

Abstract

Subtle variation in echolocation call characteristics limits identification of closely related sympatric bat species acoustically. While Myotis septentrionalis is a forest interior specialist and Myotis lucifugus is a generalist, under many circumstances echolocation call characteristics overlap. During the late summer and early fall, a large migratory event involving the Hayes Cave site in Nova Scotia allowed for assessment of echolocation call structure of the two species. We captured and recorded echolocation sequences of known species by gluing a glow stick externally between the scapulae so we could visually track and acoustically record their echolocation calls. Discriminate function analysis of call characteristics yielded a protocol which resulted in a correct species identification of 96.2% for M. lucifugus and 97.5% for M. septentrionalis.