![]() ![]() This paradigm focuses on relatively simple predator-herbivore-plant and apex predator-mesopredator-prey interactions. Although nature is rarely so black and white, the “big things run the world” paradigm has been well supported by a large body of literature on the direct and indirect effects of top predators, including trophic cascade and mesopredator release theory ( Ritchie and Johnson, 2009 Levi and Wilmers, 2012). John Terborgh countered that in fact big things such as large-bodied ungulates and top predators run the world ( Terborgh, 1988). Wilson famously postulated that little things – invertebrates – run the world ( Wilson, 1987). Our review and empirical data highlight key knowledge gaps and research opportunities to understand the complex ecosystem effects related to bear-salmon interactions. First, deer densities appear to be consistently higher on islands with abundant brown bears than adjacent islands with black bears and wolves, and moose calf survival is higher at low bear densities (25 bears per 100 km 2). In addition to our review of the literature, we present original data to demonstrate two community-level patterns that are currently unexplained. Here we review the biogeography of bear-salmon interactions and the role of salmon-subsidized bears in (1) resource provisioning to plants and scavengers through the distribution of salmon carcasses, (2) competition among bears and other large carnivores, (3) predation of ungulate neonates, (4) seed dispersal, and (5) resource subsidies to rodents with seed-filled scats. In coastal temperate ecosystems throughout much of the Northern Hemisphere, anadromous salmon once supported abundant bear populations, but both taxa have declined or been extirpated from large parts of their former ranges with limited research on the consequences of diminished or absent interactions among species. 12Department of Environmental Studies, University of California, Santa Cruz, Santa Cruz, CA, United StatesĪpex predators play keystone roles in ecosystems through top-down control, but the effects of apex omnivores on ecosystems could be more varied because changes in the resource base alter their densities and reverberate through ecosystems in complex ways.11Oregon Department of Fish and Wildlife, Salem, OR, United States.10Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, United States.9Department of Fish and Wildlife Sciences, University of Idaho, Moscow, ID, United States.8Raincoast Conservation Foundation, Sidney, BC, Canada.7Department of Geography, University of Victoria, Victoria, BC, Canada.6Hakai Institute, Heriot Bay, BC, Canada.5Alaska Department of Fish and Game, Division of Wildlife Conservation, Juneau, AK, United States. ![]() 4School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States.3Ecofish Research Ltd., Victoria, BC, Canada.2National Park Service, Alaska Region, Anchorage, AK, United States.1Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, United States.Darimont 6,7,8, William Deacy 1, Sophie L. Those bears near human civilization learn very quickly that garbage can be a good source of food.Taal Levi 1*, Grant V. However, in less harsh climates bears will be found scavenging winter kill, birdseed, grubs and/or garbage. They begin scavenging the remains of other animals.ĭepending on the climate, bears may hibernate for winter, in which case they do not eat or drink. Coastal bears will fish during the salmon run. When fall sets in, bears begin to prepare for the winter by stocking up as much as they can. They continue eating an omnivore diet, but they start to snack on the more seasonal things such as berries, honey and nuts and fish. Brown bears will even hunt for small rodents as sources for protein.Īs summer hits they begin eating grubs, roots, greenery. They will be scavenging for any early vegetation growth and/or winter-killed game animals. They mainly feed in the morning and evening to evade the heat of the day, but are known to travel long distances for food sources.Īfter a long winter of hibernation you’ll find bears on the sunny south-facing slopes, grazing on the new grass like cattle. The seasons dictate what they can eat during that specific time. This means that they eat a combination of plants and animals that are available. For the most part, however, all of the subspecies are considered to be omnivorous opportunistic scavengers. The biggest distinguishing factor is their geographic location, which dictates their popular food sources. The subspecies in America are coastal brown bear, kodiak, and grizzly. The brown bear is one species of bear that has several subspecies. ![]()
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