A NEW EXAMINATION OF ECHOLOCATION CALLS OF SOME NEOTROPICAL BATS (EMBALLONURIDAE AND MORMOOPIDAE)

In northwestern Belize, two emballonurids (Rhynchonycteris naso and Sa ccopteryx bilineata) and three mormoopids (Pteronotus parnellii, P. da vyi, and P. personatus) were examined acoustically with the Anabat II bat detector and associated analysis system, R. naso used calls consis ting of a short constant frequency (CF) at 47 kHz and concave downward frequency modulated (FM) sweep to ca. 40 kHz with two strong harmonic s. Echolocation sequences of S. bilineata revealed a paired cadence of calls. Both signals in a pair slowly Increased in frequency, forming a quasi-CF (QCF) component and terminated with a short, downward FM sw eep. The initial call of a pair ranged from 44.5 to 46.6 kHz and the s econd ranged from 46.6 to 48.7 kHz. P. parnellii used a long CF call a t 63.5 kHz, with a terminal downward FM sweep to ca. 54.5 kHz, P. davy i produced calls with an initial short CF at 68.1 kHz, a downward FM s weep, and a terminal short CF at 58.0 kHz. P. personatus emitted calls similar in shape to P. davyi, with the initial CF at. 83.0 kHz and th e terminal CF at ca. 68.0 kHz. Previous descriptions of echolocation c alls for these species compare favorably with those obtained in this s tudy, but the Anabat equipment generally revealed more variation and d etail than previously described. The echolocation calls described in t his study provide precise vocal signatures for the accurate identifica tion of free-flying individuals of the species studied.