Date of this Version
The introduced black rat (Rattus rattus) and the endemic giant fruit bat (Pteropus giganteus ariel) are serious depredators of coconuts and fruits, respectively, in the Maldives. Differences in reproductive rate between rats (high) and bats (low) must be considered in implementing control programs. We estimate a rat population can fully recover from an island-wide reduction of 90% in less than 6 months. In contrast, a bat population may require 6 years to recover from a 90% reduction. Crown-baiting of coconut palms with anticoagulant rodenticides is effective in reducing rat damage, but villagers have been reluctant to adopt recommended baiting programs, allowing rat populations to quickly recover. We substantially reduced bat populations on islands (e.g., from 2.1 bats/ha to 0.7 bats/ha) after a few nights of mist netting and recommend this procedure for managing bat populations. Bat populations should not be reduced below 0.25 bats/ha on islands in the Maldives.