Carnivore carrying behavior as documented with wildlife camera traps

Carrying behavior is exhibited for myriad purposes by a variety of animals, including mammalian carnivores, but it has been poorly studied. We used wildlife camera data to document and describe carrying behavior in a suite of native and domestic mammalian carnivores in Colorado, USA. Our objectives were to estimate the carrying rate for each carnivore species, assess the relationship between carrying rate and carnivore body mass, compare items carried to known diets and with proximity to urbanization, and explore seasonal variation in carrying rate. We documented carrying behavior in red foxes (Vulpes vulpes), coyotes (Canis latrans), bobcats (Lynx rufus), gray foxes (Urocyon cinereoargenteus), pumas (Puma concolor), and domestic cats (Fells cams). These carnivores carried objects at relatively low rates (range 0.44%-3.40%), although smaller-bodied carnivores carried items at greater rates than larger-bodied species. Prey items recorded by remote cameras were consistent with vertebrates known to be consumed by each species, and anthropogenic and synanthropic items were more common near the wildland-urban interface. For red fox, the species with the largest sample of carrying events, the rate of carrying varied by season, with increased rates during spring and summer months. Systematic exploration of carrying behavior has the potential to lend insight into carnivore diet in space and time and into shifts in dietary patterns along the wildland-urban interface. We demonstrate the power of camera trap data to examine these relationships and encourage further research of carrying behavior.