Deliberate insectivory by the fruit bat Pteropus poliocephalus by aerial hunting

The diet of the Old World fruit bats (Pteropodidae) has been well studied with a large inventory of nectar and fruit bearing plant species known to be consumed. It is far less certain, however, whether pteropodid bats intentionally supplement their diet with insects in a similar fashion to many other frugivorous and nectivorous species, including some New World fruit bats of the family Phyllostomidae. Several reports of pteropodid bats consuming insects in captivity exist, and insects have been found in the faeces and digestive tracts of some wild pteropodid bats, although their ingestion was initially thought to be accidental. However, more recent observations of large insects in faeces of wild bats, coupled with two reports (one anecdotal) of observed intentional insectivory in the wild, suggest that intentional insectivory by pteropodid bats may be more common than previously thought. In addition, reports of intentional insectivory to date have been of bats catching insects from a stationary position, and a large question still remains as to the ability of pteropodid bats to catch insects in flight without the use of laryngeal echolocation. Here, we report on an observation of intentional insectivory by a group of grey-headed flying foxes (Pteropus poliocephalus) actively preying on, and consuming, numerous (> 20) cicadas (Psaltoda sp.) by aerial hunting in southeastern Australia. We conclude that deliberate insectivory is likely an evolved and fixed component of the grey-headed flying fox's dietary ecology, and suggest that this may be an adaptation more common among pteropodid bats than previously thought