Observations of Mariana Fruit Bats (Pteropus mariannus) in the upper Talofofo watershed on southern Guam

Mariana fruit bat populations ( Pteropus mariannus) on Guam have declined dramatically since the 1950s. The last island-wide survey in 1984 estimated 450-525 animals on northern Guam; no bats were counted on southern Guam. During June-July 1996, we conducted early morning surveys for Mariana fruit bats from eight stations in the upper Talofofo River watershed on southern Guam. We recorded three sightings of solitary bats in flight. We also compiled 35 incidental obser- vations of mostly solitary bats from 1985-1999. Our data suggest that small numbers of fruit bats reside in the watershed, primarily on lands protected by a U.S. Navy base. Disturbance associated with poaching may preclude larger roosts.