Prey preferences of the coyote (Canis latrans) throughout its North American distribution

The coyote Canis latrans is one of the most studied species in North
America with at least 510 papers on its diet alone. While this research
has yielded excellent reviews of what coyotes eat, it has been inadequate
to draw deeper conclusions because no synthesis to date has considered
prey availability. We accounted for prey availability by investigating the
prey preferences of coyotes across the species’ distribution using the
traditional Jacobs’ index method, as well as the new iterative preference
averaging method on scats and biomass. We found that coyotes preferred
Dall’s sheep Ovis dalli, white-tailed deer Odocoileus virginianus, eastern
cottontail rabbits Sylvilagus floridanus and California voles Microtus
californicus, which yielded a predator to preferred prey ratio of 1:2. We
also found that coyotes avoided preying on other small mammals, including
carnivorans and arboreal species. There was strong concordance between the
traditional and iterative preference averaging method on scats, but this
pattern was not detected when biomass was considered. General linear
models revealed coyotes preferred to prey upon larger species that were
riskier to hunt, reflecting their ability to hunt in groups, and were
least likely to hunt solitary species. Coyotes increasingly preferred mule
deer O. hemionus and snowshoe hares Lepus americanus at higher latitudes,
whereas black-tailed jackrabbit Lepus californicus were increasingly
preferred towards the tropics. Mule deer were increasingly preferred at
higher coyote densities, while black-tailed jackrabbit were increasingly
avoided at higher coyote densities. Coyote predation could constrain the
realized niche of prey species at the predator species’ distributional
limits through their increased efficiency of predation reflected in
increased prey preference values. These results are integral to improved
understandings of coyote ecology and can inform predictive analyses
allowing for spatial variation, which ultimately will lead to better
understandings about the coyote’s ecological role across different
ecosystems.