Inventory of insectivorous bats on Mount Makiling, Philippines using echolocation call signatures and a new tunnel trap

The call signatures of sixteen Philippine insectivorous bat species are described, and used to inventory bats on Mount Makiling, Luzon. I compare these acoustic diversity data to those collected with mist nets, and a newly designed tunnel trap. The Rhinolophidae used calls with unique constant frequency components. Most vespertilionid calls could be identified to species based on call shape and minimum frequency, with the exception of those used by Pipistrellus spp. and Miniopterus schreibersii. The tunnel trap, mist nets, and the Anabat II detector recorded 22 species, including eight new records for Mount Makiling. Eighteen percent of the species were captured in mist nets, 68% were trapped, and 77% were detected acoustically. Twenty species were recorded either acoustically or with the trap. Two species were recorded exclusively with mist-nets, three with the tunnel trap, and four were only detected with the bat detector. Generally, bats possessing low intensity calls were not detected acoustically or captured in mist nets, but were captured in the tunnel trap. The tunnel trap captured most species flying below the canopy and the bat detector was effective for inventorying those flying above.