thumbnail

Grizzly bear predation links the loss of native trout to the demography of migratory elk in Yellowstone

Proceedings of the Royal Society B: Biological Sciences

By:
, , , , , , , , , , and
DOI: 10.1098/rspb.2013.0870

Links

Abstract

The loss of aquatic subsidies such as spawning salmonids is known to threaten a number of terrestrial predators, but the effects on alternative prey species are poorly understood. At the heart of the Greater Yellowstone ecosystem, an invasion of lake trout has driven a dramatic decline of native cutthroat trout that migrate up the shallow tributaries of Yellowstone Lake to spawn each spring. We explore whether this decline has amplified the effect of a generalist consumer, the grizzly bear, on populations of migratory elk that summer inside Yellowstone National Park (YNP). Recent studies of bear diets and elk populations indicate that the decline in cutthroat trout has contributed to increased predation by grizzly bears on the calves of migratory elk. Additionally, a demographic model that incorporates the increase in predation suggests that the magnitude of this diet shift has been sufficient to reduce elk calf recruitment (4–16%) and population growth (2–11%). The disruption of this aquatic–terrestrial linkage could permanently alter native species interactions in YNP. Although many recent ecological changes in YNP have been attributed to the recovery of large carnivores—particularly wolves—our work highlights a growing role of human impacts on the foraging behaviour of grizzly bears.

Geospatial Extents

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Grizzly bear predation links the loss of native trout to the demography of migratory elk in Yellowstone
Series title:
Proceedings of the Royal Society B: Biological Sciences
DOI:
10.1098/rspb.2013.0870
Volume
280
Issue:
1762
Year Published:
2013
Language:
English
Publisher:
The Royal Society
Contributing office(s):
Wyoming Cooperative Fish and Wildlife Research Unit
Description:
20130870
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Proceedings of the Royal Society B: Biological Sciences
Country:
United States
Other Geospatial:
Yellowstone National Park