Mesopredator release and bird extinctions in a fragmented urban landscape

In this widely cited study from San Diego habitat fragments, the authors showed that where bobcats and coyotes disappeared from small, isolated canyons, populations of smaller predators such as domestic cats and foxes increased, driving declines and local extinctions of scrub-breeding birds. This mesopredator-release dynamic demonstrated that losing larger carnivores from urban fragments cascades through the food web with concrete consequences for biodiversity. The work established habitat fragments and their carnivore occupancy as determinants of bird persistence, and it became a foundational reference for understanding why retaining bobcats and other top mesopredators matters for urban ecosystem function.