DIET COMPOSITION OF MOUNTAIN LIONS ON THE MODOC PLATEAU.
Jonathan D. Ewanyk; Institute for Wildlife Studies; 140 H Street, Blue Lake, CA, 95525; (707) 844-3516; Ewanyk@Iws.org; David K. Garcelon, Micaela S. Gunther
Diet composition of mountain lions (Puma concolor) varies regionally and is central to understanding the dynamics of predator-prey interactions. In a 2014-16 study, the Institute for Wildlife Studies found that the majority of known mortalities for collared adult female pronghorn (Antilocapra americana) on the Modoc Plateau were attributed to mountain lions. To better understand prey selection by mountain lions in this montane desert ecosystem, 21 mountain lions (14 male, 7 female) were fitted with GPS collars and monitored for hunting behavior. From February 2016 through August 2018, we investigated 258 GPS clusters (spatially aggregated points) to determine feeding events of large prey items. We found mule deer (Odocoileus hemionus) to be the primary prey, followed by feral horses (Equus caballus), coyotes (Canis latrans), livestock, pronghorn, and elk (Cervus canadensis). Mule deer were observed in the diet of all study animals except for one male, which predominately preyed on feral horses. Diet composition in this high desert ecosystem may be influenced by habitat characteristics, which are currently being investigated as part of a broader study. We hope to elucidate the relationship between habitat and prey selection for this cosmopolitan carnivore prior to impending wolf recolonization of the study area.
Poster Session   Student Paper