Occupancy of the Invasive Feral Cat Varies with Habitat Complexity

The domestic cat (Felis catus) is an invasive exotic in many locations around the world and is thought to be a key factor driving recent mammal declines across northern Australia. Many mammal species native to this region now persist only in areas with high topographic complexity, provided by features such as gorges or escarpments. Do mammals persist in these habitats because cats occupy them less, or despite high cat occupancy? We show that occupancy of feral cats was lower in mammal-rich habitats of high topographic complexity. These results support the idea that predation pressure by feral cats is a factor contributing to the collapse of mammal communities across northern Australia. Managing impacts of feral cats is a global conservation challenge. Conservation actions such as choosing sites for small mammal reintroductions may be more successful if variation in cat occupancy with landscape features is taken into account.

家猫（Felis catus）在全球多数区域均为外来入侵物种，被视为近期推动澳大利亚北部哺乳动物种群衰退的关键因子。当前该区域的诸多本土哺乳动物物种，仅能存续于由峡谷、陡崖等地貌形成的高地形复杂度生境中。那么，哺乳动物为何能在这类生境中存活？是因为野猫（feral cat）在其中的生境占据率更低，还是尽管野猫占据率较高，哺乳动物仍得以存续？本研究证实，在哺乳动物资源丰富且地形复杂度高的生境中，野猫的生境占据率显著更低。上述结果支持了这一观点：野猫的捕食压力是导致澳大利亚北部哺乳动物群落衰退的重要因素。管控野猫的生态影响是一项全球性的保护难题。若能将景观特征对猫科动物占据率的影响纳入考量，诸如遴选小型哺乳动物再引入的选址等保护行动，其成功率或将大幅提升。