The Comparative Effects of Large Carnivores on the Acquisition of Carrion by Scavengers

Abstract

Pumas (Puma concolor) and black bears (Ursus americanus) are large carnivores that may influence scavenger population dynamics. We used motion-triggered video cameras deployed at deer carcasses to determine how pumas and black bears affected three aspects of carrion acquisition by scavengers: presence, total feeding time, and mean feeding-bout duration. We found that pumas were unable to limit acquisition of carrion by large carnivores but did limit aspects of carrion acquisition by both birds and mesocarnivores. Through their suppression of mesocarnivores and birds, pumas apparently initiated a cascading pattern and increased carrion acquisition by small carnivores. In contrast, black bears monopolized carrion resources and generally had larger limiting effects on carrion acquisition by all scavengers. Black bears also limited puma feeding behaviors at puma kills, which may require pumas to compensate for energetic losses through increasing their kill rates of ungulates. Our results suggest that pumas provide carrion and selectively influence species acquiring carrion, while black bears limit carrion availability to all other scavengers. These results suggest that the effects of large carnivores on scavengers depend on attributes of both carnivores and scavengers (including size) and that competition for carcasses may result in intraguild predation as well as mesocarnivore release.

Vertebrate scavenger guild composition and utilization of carrion in an East Asian temperate forest

“…(c) How do scavenger species vary in their feeding durations on the carcasses? We hypothesized that Asian black bears would feed for longer durations than other scavengers based on bears being dominant scavengers in other ecosystems (Allen et al, ; Krofel, Kos, & Jerina, ). We also hypothesized that raccoon dogs might scavenger for longer durations than other scavengers due to being the most frequent scavenger in other studies in Japan (Sugiura & Hayashi, ; Sugiura et al, ) and therefore possibly more dependent on carrion than other species.…”

Mesopredator spatial and temporal responses to large predators and human development in the Santa Cruz Mountains of California

“…Levi and Wilmers (2012) demonstrated an ''intraguild cascade'' in which the apex predator, gray wolves (Canis lupus), suppressed the mesopredator, coyotes (Canis latrans), and thereby released the smaller red foxes (Vulpes vulpes). In addition, carrion provided by apex predators can serve as an important food source for smaller predators (Allen et al, 2015a;Ruth and Murphy, 2009;Selva et al, 2005;Wilmers and Getz, 2005). Therefore, the relationship between dominant and smaller predators may reflect a complex balance of risk-avoidance and energetic needs, all of which may be influenced by anthropogenic subsidies and disturbances and direct predation.…”

Multiple anthropogenic interventions drive puma survival following wolf recovery in the Greater Yellowstone Ecosystem

“…Pumas ( Puma concolor ) are solitary carnivores and, like wolves, important components of ecological communities (Allen, Elbroch, Wilmers & Wittmer, ; Elbroch, Peziol, O'Malley & Quigley, ). They are also a conservation success story, in that puma populations rebounded in the west of the United States and Canada after 1965, when wildlife managers in nearly every western state stopped paying state bounties for killing pumas and introduced managed puma hunting with limits in restricted seasons (Mattson & Clark, ).…”