Participating Faculty
Robert Weilgus

Robert Wielgus

Department:School of the Environment
Office:Heald 515
Mailing Address:School of the Environment
PO Box 646410
Pullman, WA 99164-6410

Research Interests

Population, behavioral, and habitat ecology of large carnivores (grizzly bears, black bears, cougars, wolves) and their prey (mountain caribou, mule deer).

Research Summary

My research focuses solely on large-scale, long-term field experiments on cascade effects of human disturbance (hunting, forestry, agriculture) on population, habitat, and community ecology of large carnivores (wolves, grizzly bears, brown bears, black bears, cougars, lynx) and their prey (mountain caribou, elk mule deer, white-tailed deer, livestock ,and snowshoe hares).

For example, my work on effects of human hunting of carnivores showed increased (not decreased!) predator/prey/human conflicts because of compensatory reproduction by wolves and compensatory immigration by bears and cougars. Increased hunting of wolves caused increased breeding pairs and per capita reproduction. Increased hunting of bears and cougars caused increased immigration by male bears and male cougars and caused increased sexually selected infanticide, sexual habitat segregation, and prey switching by females with cubs. Females switched from normal abundant prey (white-tailed deer) to rare (mule deer) and threatened (caribou) prey to avoid the new infanticidal males. For all 3 carnivores (wolves, bears, cougars), increased hunting caused increased (not decreased) predation, complaints, and livestock depredations. These field experiments were paradigm-changing for our understanding complex human/predator/prey interactions and unanticipated cascade effects of hunting large carnivores.

My research has resulted in “on the ground” legislative and policy changes for conservation of wolves, grizzly bears, European brown bears, cougars, and wolves. For example: my work resulted in elimination of hunting of grizzlies in southern BC and all of Alberta, recovery of a threatened grizzly bear population in northern Idaho, reduced and sustainable hunting of grizzlies in central and northern BC, establishment of 7 grizzly bear preserves in BC, recovery of an endangered brown bear population in France, reduced and sustainable hunting of cougars in WA, OR, and MT, and implementation and acceptance of the WA State wolf recovery and wolf/livestock programs. See Service to the State(s) for details.

Because of the success of my work on bears, cougars, and wolves, I was appointed as Program Leader for wolf/livestock research & extension in WA by the WA State Legislature in 2013.

Research Publications

(*Preceding authors are my grad students1 or post-docs2.)

*2 Maletzke, B.T., Wielgus, R.B., Pierce, D.J., Martorello, D., and Stinson, D. 2015. A meta-population model to predict occurrence and recovery of wolves. Journal of Wildlife Management. DOI: 10.1002/jwmg.1008.

1Keehner, J.N., Wielgus, R.B., and, Keehner, A.M. 2015. Effects of male targeted hunting regimes on prey switching by female mountain lions: implications for apparent competition on declining secondary prey. Biological Conservation. 192:101-108.

1Keehner, J.N., Wielgus, R.B., Maletzke, B.T., and Swanson, M.E. 2015. Effects of male targeted harvest regime on sexual segregation in mountain lion. Biological Conservation. 192:42-47.

Wielgus, R.B. and Peebles, K.A., 2014. Effects of wolf mortality on livestock depredations. PloS One. DOI: 10.1371/journal.pone.0113505.

1Maletzke, B.T., Wielgus, R.B., Koehler, G.M., Swanson, M.E., Cooley, H.S., and Alldredge, J.R. 2014. Effects of hunting on cougar spatial organization. Ecology and Evolution. DOI: 10.1002/ece3.1089.

1 Peebles, K.A., Wielgus, R.B. Maletzke, B.T., and Swanson, M.E. 2013. Effects of remedial sport hunting on cougar complaints and livestock depredations. PLoS One. 8 (13): e79713.

Wielgus, R.B., 1 Morrison, D.E., Cooley, H.C., and Maletzke, B.T. 2013. Effects of male trophy hunting on female carnivore population growth and persistence. Biological Conservation. 167:69-75.

2 Chapron, G., Wielgus, R., Lambert, A. 2012. Overestimates of maternity and population growth rates in multi-annual breeders. European Journal of Wildlife Research. DOI 10.1007/s10344-012-0671- x (Oct 2012).

Washington State University