CAREER: Integrating positive and negative interactions in carnivore community ecology

University Of Washington, Seattle WA

Investigators

Abstract

Large carnivores are key components of ecosystems, but the ability of scientists to predict their cascading effects on the abundance and behavior of other species remains alarmingly poor. Large carnivores can reduce populations of smaller carnivore species through killing and intimidation, but large carnivores may also benefit some smaller carnivore species by providing them with easy meals in the form of carrion left on carcasses of animals killed by large carnivores. An improved understanding of the role of large carnivores in ecosystems is critical, because rapidly changing carnivore distributions are creating unprecedented challenges to societies worldwide. This study will examine positive and negative relationships among carnivore species in an integrated framework, providing new insights that will improve carnivore conservation and management in a changing world. This research will be incorporated into a wildlife course with 150 students per year by creating new inquiry-based labs using photos from carcass sites. In addition, this study will involve Alaska Native students in field and lab research in partnership with the Alaska Native Science and Engineering Program, and video vignettes about carnivore ecology will be created in partnership with Symbio Studios to reach 2 million K-12 students per year for 5-7 years. This study will examine the movements and population dynamics of two common mesopredators, coyotes and bobcats, as part of a new collaborative study of wolves, cougars, deer, and elk in northern Washington. Wolves are naturally recolonizing Washington, creating a mosaic of variation in large carnivore presence. A powerful combination of animal-borne GPS and video tracking technology, stable isotope enrichment of carcasses, fecal genotyping, and cameras at kill sites will be used to jointly examine positive and negative relationships among carnivores. The researcher hypothesizes that scavenging is a critical yet overlooked factor determining mortality risk for mesopredators, creating hotspots of negative species interactions across the landscape. Carrion may thus present a "fatal attraction" whereby local-scale clustering of competing carnivores leads to landscape-scale suppression of subordinate mesopredators. Coyotes and bobcats will be used to test this hypothesis, because they differ strongly in their scavenging activity but are otherwise ecologically similar.