6 Competition and Symbiosis: The Indirect Effects of Predation

摘要: The greater Yellowstone ecosystem supports a diverse and abundant group of large predators and ungulates, with six large predators (black bears, coyotes, grizzly bears, humans, cougars, wolves) and eight large ungulates (bighorn sheep, bison, elk, moose, mountain goats, mule deer, pronghorn, and white-tailed deer). The concentration of ungulates on lower-elevation winter ranges in northern and west-central Yellowstone increases spatial overlap and the potential for competition between cougars, coyotes, wolves, and bears in the spring after hibernation. Conversely, the migration of ungulates to summer ranges and a substantial increase in ungulate numbers in the park, including alternate and smaller prey, may alleviate dietary and spatial overlap between predator species (Murphy 1998; Metz 2010; PJ White et al. 2010). Previous studies of systems with one or two predator and prey species suggested that …