Mesopredators display behaviourally plastic responses to dominant competitors when scavenging and communicating

Abstract

Mesopredators face interspecific competition and intraguild predation when sharing resources with apex predators or more dominant mesopredators. We theorize that mesopredators use a variety of tactics to avoid competitively dominant predators at shared locations, such as scavenging and communication sites, that provide a mix of risks and rewards to these smaller predators. We examined whether mesopredator species employed behavioural tactics to reduce risks from dominant pumas when exploiting resources. We monitored carcasses in the Santa Cruz Mountains, CA across a gradient of human development and treated half of the carcasses with puma sign. Bobcats visited treated carcasses significantly later and for less time. Contrary to our expectations, coyotes and grey foxes were more likely to visit treated carcasses, although foxes were significantly less likely to visit a carcass also used by coyotes. Bobcats and foxes were less likely to visit carcasses at higher development levels whereas raccoons exhibited the opposite pattern. At communication sites, we observed temporal segregation among mesopredators and pumas. Coyotes and small predators exhibited the most segregation, followed by coyotes and pumas, and raccoons and pumas. Our results suggest subordinate predators employ a combination of spatial and temporal avoidance to minimize competitive interactions at shared sites.