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Extramural Research

Grantee Research Project Results

Grantee Research Project Results

The Role of Wolves as a Keystone Species: Examining the Ecological Effects and Conservation Implications of a Reintroduced Top Predator on the Scavenger Guild, Yellowstone National Park

EPA Grant Number: U915997
Title: The Role of Wolves as a Keystone Species: Examining the Ecological Effects and Conservation Implications of a Reintroduced Top Predator on the Scavenger Guild, Yellowstone National Park
Investigators: Wilmers, Christopher C.
Institution: University of California - Berkeley
EPA Project Officer: Boddie, Georgette
Project Period: January 1, 2001 through January 1, 2004
Project Amount: $80,640
RFA: STAR Graduate Fellowships (2001)
Research Category: Fellowship - Terrestrial Ecology and Ecosystems , Academic Fellowships , Ecological Indicators/Assessment/Restoration

Description:

Objective:

The gray wolf was reintroduced to Yellowstone National Park in the spring of 1995, after a 70-year absence. In the past 6 years, the population has grown from 31 released animals to more than 100 individuals, as wolves have exploited an abundant elk population. Consequently, elk that had previously experienced significant mortality primarily in the late winter because of starvation now face mortality throughout the year. When an elk is killed by wolves, its carcass is partially consumed by the wolves and then is scavenged extensively by eight other carnivore species (coyote, bald eagle, golden eagle, grizzly bear, black bear, raven, magpie, and red fox) and less intensely by up to 20 other species. Field observations indicate that the infusion of wolf-killed ungulate carrion throughout the year has created an abundant and dependable food source for these other carnivores. The objective of this research project is to explore the consequences of this supplemental food resource on scavenger community dynamics.

Approach:

By changing the temporal distribution and quantity of carrion and thereby reducing/accentuating food shortages for scavengers during lean periods, wolves may act to stabilize or destabilize dynamics. I have been collecting field data for 3 years on consumption rates of scavengers at wolf-killed ungulate carcasses, and currently am developing models to examine the change in flow of kilocalories from ungulate to scavenger communities because of wolf reintroduction.

Supplemental Keywords:

fellowship, wolves, carnivore species, carnivores, conservation implications, ecological effects, top predator, Yellowstone National Park, scavenger communities, scavengers.

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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