Data from: Residential development reduces black bear (Ursus americanus) opportunity to scavenge cougar (Puma concolor) killed prey

Large carnivores commonly scavenge on kills made by other species, but if
and how this phenomenon is influenced by urbanization remains unclear. To
address this knowledge deficit, we investigated whether housing density,
along with demographic and environmental covariates, impacted the
probability of American black bear (Ursus americanus) occurrence at cougar
(Puma concolor) killed prey along the wildland-urban gradient of western
Washington, USA. Under the refuge hypothesis, which stipulates residential
development reduces opportunities for black bears to visit cougar prey
carcasses by 1) altering cougar kill composition, and/or 2) drawing black
bears to human subsidies, we expected the probability of bear presence at
cougar kills to decline as housing density increased. Alternatively, under
the pile-up hypothesis whereby reduced green space drives greater overlap
and thus more frequent interactions among carnivores, we predicted that
bear presence at cougar kills would increase with housing density.
Occupancy models derived from forensic and remote camera evidence of bear
visitation to carcasses at kill sites identified from 12 GPS-collared
cougars indicated that the probability of bear presence at kill sites
decreased when cougars foraged on small-bodied prey, increased in summer
compared to autumn, and declined with increasing housing density. Indeed,
the top model indicated a multiplicative decrease of 500 in the odds of
black bear carcass visitation for every additional house/ha on the
landscape, supporting the refuge hypothesis. These results suggest that
residential development has the potential to alter intraguild
relationships among large carnivores, even at modest levels where robust
carnivore populations persist on the landscape, and may alter scavenger
dynamics at carcasses where black bear presence is virtually eliminated.