Surveying Potential Predators to Protect a Critically Endangered Bahamian Songbird

Abstract

The Bahama Oriole (Icterus northropi) is a critically endangered songbird that is only present on the Andros island complex in the Bahamas, and whose cause of decline is not well understood. In order to gauge the threat predation poses to this species, we surveyed populations of two globally invasive songbird predators: black rats (Rattus rattus) and house cats (Felis catus). Both species have contributed to the decline of several island birds worldwide, including other Caribbean songbirds. In January 2017, we monitored the presence of house cats using trail cameras and were able to capture images of cats in known Bahama Oriole habitats. In May 2018, we utilized wax baits to survey the population of black rats; while we found no signs of rats in this survey, several of our baits were attacked by land crabs. Our combined survey results indicate that while black rat population density is likely very low, house cats are present in Bahama Oriole nesting habitats and are more likely to be a threat. In order to determine the extent of this threat and how it should be countered, Bahama Oriole predator research should shift focus from black rats to house cats.