ONTOGENY OF VOCALISATIONS IN INFANT BLACK FLYING FOXES, PTEROPUS ALECTO

Abstract

AbstractMost mega and microchiropteran bats live in large colonial roosts where potential intermingling of mother-infant pairs places immediate demands on their recognition systems. In microchiropteran bats, infants produce distinct isolation calls that appear to become less complex in structure in the latter stages of lactation. This results in a reduction in the capacity of females to locate their infants. Similar recognition pressures exist for both suborders therefore it might be expected that they would exhibit similarities in their vocal development. This study quantifies the vocal characteristics of infant black flying foxes, Pteropus alecto, to assess vocal development in this species. Recordings were made of 21 infants, nine males and twelve females, between 1 and 35 days in age. As in microchiropteran bats, infant black flying foxes produce individually distinctive calls, which persist throughout lactation. Unlike microchiropterans, calls remained stable in structure throughout lactation. Individuals produced one of three distinctive isolation call types. Whether mothers use this variation to recognise patches of infants that include their own within a camp or to locate their own infants requires further study.