Bob Crabtree

Read Dr Crabtree’s Open Letter on killing contests here.

Read Coyotes and Canid Coexistence in Yellowstone by Robert L. Crabtree & Jennifer W. Sheldon here.


Bob is Chief Scientist at the Yellowstone Ecological Research Center (YERC) in Bozeman, Montana and is Research Associate Professor in the Department of Ecosystem and Conservation Sciences at the University of Montana in Missoula, Montana. He became fascinated with the process of predation at an early age and published his first paper as an undergraduate at the University of Idaho on competitive interactions between two species of flycatchers while working in the North Cascades. He received his MS from Utah State University, where he examined predation on waterfowl nests at Bear River Migratory Bird Refuge. He received his PhD at the University of Idaho, where he focused his dissertation on coyote population demography and social structure.

His seminal work on coyotes in central Washington (1984 thru 1988) and on Yellowstone’s northern range (1989 thru 2009) formed the basis for a new understanding of coyote ecology and population demography. He has defined numerous mechanisms regarding the powerful demographic and behavioral response coyotes have to human exploitation and wolf impacts. From a scientist’s viewpoint, he has challenged the ecological and economic validity of indiscriminate killing of coyote (and carnivore) populations. He has also conducted studies on wolves, foxes, bears, felids, mustelids and raptors, and has specialized in the analysis of long-term time-series data sets on many vertebrate species populations.

He began working on research projects in Yellowstone National Park immediately after the Great Fires of 1988. His primary focus at that time was predator-prey relations, population modeling, and carnivore behavior. Soon after becoming established in Yellowstone with a variety of ecological research projects, he founded YERC based on three pillars: (1) long-term research and monitoring, (2) large spatial scale landscape ecology, and (3) building collaborative partnerships with decision-makers. Increasing the role of science at the decision-making table and seeking innovative ways to bridge the gap between scientists and practitioners has been a primary concern in his career. This has led to his interest in spatio-temporal predictive modeling of species populations and ecological forecasting of communities. The bio-political atmosphere at Yellowstone, along with his four-year appointment with the Department of Energy in Washington, has certainly molded his career track. He continues to strive to ‘translate’ the results of ecological research into informed decision-making and on-the-ground conservation action.

Bob’s continued long-term research in Yellowstone led to expansion into remote sensing applications in ecology to provide scientists and decision-makers access to landscape scale evaluations, ecosystem assessments, and important variables to understand change in species populations from climate and other environmental impacts. He also began parallel studies to understand the long-term effects of the wolf reintroduction in Yellowstone, and has taken full advantage of similar natural and policy experiments such as land-use activities, fire, floods, drought, beetle kill, and extreme weather events – all with a ‘systems’ approach. He worked with colleagues at the University of Montana to design and form a new Systems Ecology graduate program. He recently worked on developing Adaptive Impact Models (AIM) with the US Fish and Wildlife Service.

He has authored over 60 peer-reviewed publications, has crafted over 50 MOUs and cooperative agreements with federal and state agencies, and obtained funding on 80 grants that have led to another 100+ publications on collaborative projects in Yellowstone and other benchmark ecosystems.


Learning to do what’s right for carnivores.

America’s Serengeti.

Bringing back the full suite of animals.

Ranching with the natural laws of ecosystems.


Respecting an indigenous species.

The coyote’s response to the colonization of America.

Increased breeding and litter size responses.

The relationships between predators and prey.

Scaling up a successful model.

The most effective guarding animal?

Using natural systems to everyone’s benefit.

Getting ranchers involved in the naturally functioning ecosystem.

Effects of indiscriminate reduction of predator population.

The coyote’s biological response to control attempts.

Assessing the impacts of lethal control.

The Shapeshifter – Nature Documentary

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