Strategies for reducing feral cat threats to endangered Hawaiian birds

Introduced predators are one of the most important limiting factors for endemic Hawaiian forest birds. In the sub­alpine zone of Mauna Kea on the island of Hawaii, the primary predators of the endangered Hawaiian finch, palila (Loxioides bailleui), are feral house cats. Remote video monitoring revealed that feral cats are primarily diurnal predators of palila during the extended period of nestling development. Reducing this predation is necessary for population recovery and efforts to reintroduce palila to parts of their historical range. Currently, feral cats are removed with an extensive array of live traps. Since 1998, 7,344 trap nights of effort have been implemented, and although temporary declines in capture occur within seasons, cumulative capture rates show there has been little lasting effect from season to season. New emphases on improving capture efficiency include improved techniques for attracting cats to traps with lures that require infrequent refreshing or maintenance, “smart trap” technology that efficiently notifies managers when traps of all types contain animals, and adaptive strategies for managing feral cat populations in a variety of habitats and parks in the Pacific. Further documentation and interpretation of feral cat impacts on native wildlife will help prioritize and justify requests for increased funding for predator management. Accurate information on feral cat problems will help educate decision-makers and the public of the need for increased funding to protect endangered birds from this threat