WSU CAHNRS

Washington State University

School of the Environment

Watershed Lab

Steffen Center

Forestry

Earth Science/Geology

Completed Projects

clip_image002Effects of trophy hunting on grizzly bear habitat use, population growth, and persistence

R. Wielgus & others.

This project was part of Rob Wielgus’ Ph.D., post-doctoral, and professorship program. The project tested and rejected the “increased reproduction hypothesis” whereby mortality of adult males is believed to result in increased production and survival of young due to compensatory, density dependent effects. The research supported the “decreased reproduction hypothesis” whereby mortality of resident adult males results in increased immigration by potentially infanticidal males, increased sexual segregation, and reduced female reproduction, population growth, and persistence. This research started the paradigm shift for sustainable, low mortality, grizzly bear and brown bear hunting management world-wide. In addition, trophy hunting of threatened grizzly bear populations in southern BC and AB has been discontinued, and a system of 6 grizzly bear preserves have been established in BC as a result of this work.

Wielgus, R.B., and F.L. Bunnell. 1994. Dynamics of a small, hunted brown bear population Ursus arctos in southwestern Alberta, Canada. Biological Conservation. 67:161-166.

Wielgus, R.B., F.L. Bunnell, W.L. Wakkinen, and P.E. Zager. 1994. Population dynamics of Selkirk Mountain grizzly bears. Journal of Wildlife Management. 58(2):266-272.

Wielgus, R.B., and F.L. Bunnell. 1994. Sexual segregation and female grizzly bear avoidance of males. Journal of Wildlife Management. 58(3): 405-413.

Wielgus, R.B., and F.L. Bunnell. 1995. Tests of hypotheses for sexual segregation in grizzly bears. Journal of Wildlife Management. 59(3):552-560.

Wielgus, R.B., and F.L. Bunnell. 2000. Possible negative effects of adult male mortality on female grizzly bear reproduction. Biological Conservation 93:145-154. PDF

Wielgus, R.B., F. Sarrazin, R. Ferriere, and J. Clobert.  2001. Estimating effects of adult male mortality on grizzly bear population growth and persistence using matrix models. Biological Conservation. 98(3): 293-303. PDF

Wielgus, R.B. 2002. Minimum viable population and reserve sizes for naturally regulated grizzly bears in British Columbia. Biological Conservation. 106 (3): 381-388. PDF

 

clip_image002Effects of forestry on grizzly bear habitat use

R. Wielgus & others.

This project was part of Rob Wielgus’ post-doctoral and professorship program. The project tested the widely accepted, but untested, hypotheses that grizzly bears avoid managed forests and forestry roads. Grizzly bears did not avoid managed forests and forestry-only roads, but they did avoid open roads and adjacent forest types. Forestry activities by themselves (clearcuts, young second growth forests, restricted forestry-only roads) had little or no impact on grizzly bear habitat use. Human recreational use of open forestry roads had the only observed negative effect on grizzly bear habitat use and population growth. Forest road management in grizzly-occupied areas of the US and Canada has changed as a result of this work.

Wielgus, R.B., P. Vernier, and T. Schivatcheva.  2002. Grizzly bear use of open, closed, and restricted forestry roads. Canadian Journal of Forest Research. 32 (9): 1597-1606. PDF

Wielgus, R.B., and P. Vernier. 2003. Grizzly bear selection of managed and unmanaged forests in the Selkirk Mountains. Canadian Journal of Forest Research. 33: 822-829. PDF

 

clip_image002_002Effects of sex and age on black bear conifer damage and control

G. Collins, R. Wielgus & others.

This project was part of Gail Collins’s M.S. program. We examined the commonly held belief that all sexes and ages of black bears cause conifer damage and that hunting is an effective control measure. Female black bears caused 89% of total conifer damage but comprised only 31% of kills. Males caused only 11% of conifer damage but comprised 69% of kills. We suggested that current lethal control measures were relatively ineffective for reducing conifer damage and that supplemental feeding may be a more effective method for reducing damage. Methods of damage control in the Pacific Northwest were changed as a result of our work.

Collins, G.H., R.B. Wielgus, and G.M. Koehler. 2002. Effects of sex and age on American black bear conifer damage and control. Ursus. 13: 231-236. PDF

 

clip_image002_005Effects of forest fragmentation on cougar predation of endangered mountain caribou

D. Katnik, R. Wielgus & others.

This project was part of Don Katnik’s Ph.D. program. We tested the hypothesis that forest fragmentation results in increased predation by cougars on the last remaining mountain caribou population in the lower US. Results suggested that small, interspersed clear-cut’s in old-growth forest results in increased invasion by white-tailed deer and subsequent increased predation on mountain caribou by cougars.  Forest management was changed in the US and Canada, and a new caribou preserve was established in BC as a result of this work.  

Katnik, D.D., and R.B. Wielgus. 2005. Landscape proportions versus Monte Carlo simulated home ranges for estimating resource availability. Journal of Wildlife Management.  69 (1): 20-32. Awarded most outstanding article of the year by the Wildlife Society. PDF

clip_image002_005Population growth and persistence of endangered mountain caribou in the South Selkirks of WA and BC

R. Wielgus & others.

We determined rates and causes of mortality, reproduction, and population growth & persistence for the last remaining mountain caribou population in the lower US. Preliminary results suggested that this population was decreasing to extirpation.  New results indicate the population is now stable or growing.

Wielgus, R.B. 2011. Population demography and persistence for an endangered mountain caribou population. Biological Conservation. (In Prep)

 

clip_image005Cougar predation and population growth of sympatric mule Deer and white-tailed deer

H. Robinson, R. Wielgus & others.

This project was part of Hugh Robinson’s M.S. program. We tested if cougar predation for white-tailed deer (primary prey) and mule deer (secondary prey) was consistent with the apparent competition hypothesis. Results indicated that white-tailed deer were approximately 3 times as numerous as mule deer and that mule deer were declining at a rate of 22%/year – whereas white-tailed deer are increasing at 11%/yr. Predation by cougars accounted for the difference in growth rates. Forest fragmentation and agriculture may have resulted in increased numbers of white-tailed deer and cougars in mule deer range with subsequent increased predation. Results were consistent with the apparent competition hypothesis. Forestry, cougar, and deer management were changed in parts of WA, ID, and BC as a result of this work, and mule deer populations are now growing.

Robinson, H.S., R.B. Wielgus, and J.C.  Gwilliam. 2002. Cougar predation and population growth of sympatric mule deer and white-tailed deer. Canadian Journal of Zoology. 80 (3): 556-568. PDF

Wielgus, R.B, H.S. Robinson, G. Gwilliam, and J. Clobert. 2010. Tests of resource competition, apparent competition, and prey switching for declines of secondary prey. Journal of Wildlife Management. (Submitted – being revised).

 

clip_image002Minimum population size and limiting factors for grizzly bears in the North Cascades OF WA AND BC

K. Romain, R. Wielgus & others.

This project was part of Kim Romain’s M.S. program. We determined minimum population size of the North Cascades grizzly bear population in NW WA and southern BC by using DNA hair snags. Results suggested that grizzly bears were demographically extirpated (The BC and WA governments devised a recovery plan –  and possible reintroduction plan (BC only) as a result of this work.

Romain-Bondi, K, A., R.B. Wielgus, L. Waits, W.F. Kasworm,  M. Austin, and W. Wakkinen. 2004. Density and population size estimates for North Cascades grizzly bears using DNA hair sampling techniques. Biological Conservation. 117: 417-428. PDF

 

clip_image005Population growth of cougars in the Selkirk Mountains of BC, ID, & WA

C. Lambert, R. Wielgus & others.
This project was part of Catherine Lambert’s M.S. program. We tested the commonly held belief that cougars were increasing in the Selkirk Mountains as evidenced by increased cougar complaints and predation on mule deer and caribou. Contrary to accepted belief, cougars were declining rapidly due to excessive hunting mortality. We hypothesized that the high levels of hunting may have caused increased immigration by teenage male cougars – and that could have increased the number of complaints and incidents of predation on rare prey. Increasing complaints were not associated with increasing cougars. This research caused cougar managers in the Americas to re-think their assumptions that increased complaints and predation is due to increased cougars.

Lambert, C., R.B. Wielgus, Robinson, H.S., Cruickshank, H., Katnik, D.D., Clarke, R., and Almack, J.  2006.  Dynamics and viability of a cougar population in the Pacific Northwest. Journal of Wildlife Management. 70(1): 246-254. PDF

 

clip_image002_003Cougar Prey selection in a  mule deer  and white-tailed deer community

H. Cooley,  R. Wielgus & others.
This project was part of Hilary Cooley’s M.S. program. We tested and confirmed our hypotheses that cougars select for rare declining mule deer instead of abundant increasing white-tailed deer in heavily hunted northern WA. This research caused deer managers to re-think their beliefs (increased competition, reduced habitat) regarding the causes of widespread mule deer declines in parts of western North America.

Cooley, H.S., H.S. Robinson, R.B. Wielgus, and C.S. Lambert. 2008. Cougar prey selection in a white-tailed deer and mule deer community. Journal of Wildlife Management. 72(1): 99-106. PDF

 

 

clip_image007Winter Habitat use by endangered lynx in WA

B. Maletzke, R. Wielgus & others.
This project was part of Ben Maletzke’s M.S. program. We determined that endangered lynx in northern WA rely on old growth spruce and fir forests during winter – not young second growth as commonly observed in northern Canada & Alaska. Old growth forests were preserved in WA lynx range as a result.

Maletzke, B.T., Koehler, G.M., Wielgus, R.B., Aubrey, K.B., and Evans, M.A.  2008. Habitat conditions associated with lynx hunting behavior during winter in northern Washington. Journal of Wildlife Management. 72(7): 1473-1478.PDF

Koehler, G.M., Maletzke, B.T., von Kienast, J.A., Aubry, K.B., Wielgus, R.B., and Naney, R.H. 2008. Habitat fragmentation and the persistence of lynx populations in Washington State.  Journal of Wildlife Management. 72(7): 1518-1524. PDF

 

clip_image002_001Population demography and recovery of endangered European brown bears

G. Chapron, R. Wielgus & others.
This project was part of Gullaume Chapron’s Post-doctoral program. We determined that brown bears in the Pyrenees of France and Spain were declining to extirpation because of too many males and too few females. The government of France reintroduced female bears from Slovenia and the population is now growing towards recovery.

Chapron, G., R.B. Wielgus, P. Quinette, and J. Camarra. 2009. Diagnosing mechanisms of decline and planning for recovery for an endangered brown bear (Ursus arctos) population. PLoS ONE. 4(10): e7568. PDF

Chapron, G., Wielgus, R., Lambert, A. 2012. Overestimates of maternity and population growth rates in multi-annual breeders. European Journal of Wildlife Research. (Oct 2012). DOI 10.1007/s10344-012-0671-x. JIF = 1.31 PDF

 

clip_image005Effects of heavy hunting on cougar immigration and population growth

H. Robinson, R. Wielgus & others.
This project was part of Hugh Robinson’s Ph.D. program. We tested and confirmed our hypothesis that heavy hunting of cougars was compensated by increased teenage male immigration – resulting in male increase, female decrease & overall stable total numbers of cougars. Heavy hunting did not reduce cougar numbers and densities. This research started a paradigm shift on effects of hunting on cougar numbers and populations.

Robinson, H.S., Wielgus, R.B., Cooley, H.S., and Cooley, S.W. 2008. Sink populations in large carnivore management: cougar demography in a hunted population. Ecological Applications. 18(4): 1028-1037. Sink.pdf

 

clip_image005Effects of light hunting on cougar emigration and population growth

H. Cooley, R. Wielgus & others.
This project was part of Hilary Cooley’s Ph.D. program. We tested and confirmed our hypotheses that light hunting is compensated by increased teenage male emigration resulting in stable total numbers of cougars. We also showed that heavy hunting results in increased infanticide by immigrant males. Light hunting did not increase cougar numbers and densities.  This research cemented the paradigm shift on effects of hunting on cougar numbers and populations.

Cooley, H.S., Wielgus, R.B., Koehler, G.M., and Maletzke, B.T. 2009. Source populations in carnivore management: cougar demography and emigration in a lightly hunted population. Animal Conservation.12:321-328. See Source.pdf.

Cooley, H.S., Wielgus, R.B., Robinson, H.S., Koehler, G.M., and Maletzke, B.T. 2009. Does hunting regulate cougar populations? A test of the compensatory mortality hypothesis. Ecology. 90: 2913-2921. See Compensatory.pdf.

 

clip_image005Cougar prey selection in an elk & mule deer community

K. White, R. Wielgus & others.
This project was part of Kevin White’s M.S. Program. We tested and confirmed our hypotheses that male and female cougars select for different prey. Males select for larger elk and females select for smaller mule deer. Hunting of cougars to reduce predation on elk should not be as effective as previously thought if females kill very few elk and killed males are replaced by new immigrant males. This research caused elk managers to re-think their ideas that all predators are the same, have the same effects on prey, and can be controlled through remedial hunting.

White, K.S., Koehler, G.M., Maletzke, B.T., and Wielgus, R.B. 2011. Differential prey use by male and female cougars. Journal of Wildlife Management 75(5): 1115-1120. PDF

 

clip_image005Effects of hunting on cougar spatial ecology.

B. Maletzke, R. Wielgus & others.
This project was part of Ben Maletzke’s Ph.D. program. We found that heavy hunting of resident male cougars results in a doubling of immigrant male home range size and home range overlap – resulting in a doubling of cougar/human encounter probabilities. The  large home ranges also resulted in an erroneous doubling or tripling of estimated cougar densities or population sizes. Younger cougars (immigrants) used human-occupied areas more than established residents. All of these findings (not increasing cougars) could explain the increased complaints and livestock depredations in heavily hunted areas. This research caused cougar managers to re-think their beliefs on effects of remedial hunting to reduce cougar-human conflicts.

Maletzke, B.T., R Wielgus, G.M. Koehler, M. Swanson, H. Cooley, and J. Richard. 2014. Effects of hunting on cougar spatial organization. Ecology and Evolution. PDF

 

Beausoleil, R.A., Koehler, G.M., Maletzke, B.T., Kertson, B.N., and R.B. Wielgus. 2013. Research to regulation: Cougar social behavior as a guide for management. Wildlife Society Bulletin 37(3): 680-688. PDF

 

clip_image005Effects of hunting on cougar prey selection

J. Keehner, R. Wielgus & others.
This project was part of Jon Keehner’s M.S. program. We found that only female cougars with vulnerable young cubs selected for rare, declining secondary prey (mule deer) and selected against abundant, increasing primary prey (white-tailed deer).  We hypothesized that females with cubs avoid potentially infanticidal immigrant males in heavily hunted populations and switch to alternate secondary prey areas to avoid infanticide. This research started a dramatic change in cougar-prey understanding in western North America.   

Keehner M.S. thesis PDF

Keehner, J.R., Wielgus, R.B., Warheit, K.I., and Thornton, A.M. 2010. Tests of hypotheses for predator selection of declining secondary prey. Biological Conservation (Submitted – being revised).

 

 

clip_image002_003Effects of hunting on sexually segregated habitat use in Carnivores.

J. Keehner, R. Wielgus & others.
This project was part of Jon Keehner’s Ph.D. program. We tested and confirmed our hypothesis that excessive hunting of adult male cougars resulted in avoidance of immigrant males by females with young cubs because of increased infanticide. Females with cubs did not avoid resident males in lightly hunted areas. Remedial hunting of cougars actually caused increased cougar predation on rare, declining sensitive and endangered prey. This work cemented a dramatic change in cougar – prey management in WA. Excessive remedial hunting of cougars was discontinued in WA in 2011 as a result of this work.

Keehner, J.R., Maletzle, B.N. Wielgus, R.B., Koehler, G.M., and Swanson, M. 2011.  Tests of hypotheses for sexual segregation in carnivores. Ecology (Submitted – being revised).

Keehner Ph.D. dissertation PDF

 

clip_image005Effects of hunting males on female cougar population growth

D. Morrison, R. Wielgus & others.
This project was part of Dana Morrison’s M.S. program. We found that heavy hunting of males results in increased infanticide by immigrant males and severe reductions in female population growth. We also found that the intrinsic growth rate (without hunting) of cougars is +14% – not the commonly accepted 25%. This research resulted in a new “equilibrium management” policy for cougars in WA. Maximum cougar hunting mortality rates in WA were reduced to less than 14% statewide.

Morrison, D., Wielgus, R.B., Cooley, H.S., Maletzke, B.T., and Koehler, G.M. 2011. Effects of hunting males on female cougar population growth and persistence. Biological Conservation.  PDF

clip_image005Effects of hunting on cougar complaints and livestock depredations

K. Peebles, B. Maletzke, R. Wielgus & others.
This project was part of Kaylie Peeble’s Honors B.S. program. We found that increased remedial hunting of cougars did not reduce cougar complaints and livestock depredations in WA. This research resulted in new progressive legislation (equilibrium management) regarding livestock depredations. Heavy remedial hunting (> 14% yr) is no longer used in WA to reduce complaints and depredations.

Peebles, K., Wielgus, R.B., Maletzke, B.T., and M.E. Swanson. 2013. Effects of remedial sport hunting on cougar complaints and livestock depredations. PLoS One 8(11). PDF

 

clip_image009A spatially explicit, Age/stage, Metapopulation, matrix model for wolf recovery in WA

B. Maletzke & R. Wielgus.
This project was part of Ben Maletzke’s post-doctoral program. We were asked by the Washington Department of Fish & Wildlife to create a population projection model for wolf numbers & spatial occupancy for their wolf recovery plan. We built a pack-based , age/stage, metapopulation matrix model using RAMAS Landscape. The model was parameterized using demographic data from Idaho and Montana and landscape data from Washington. The model (and results) forms the basis for Washington State’s Wolf Recovery Program. So far as we know, this is the 1st use of these advanced quantitative methods to aid in recovery planning for wolves in the Rocky Mountains and Pacific Northwest. We hope to use these proven scientific methods to avoid the protracted litigation and political battles surrounding wolf recovery elsewhere.

Maletzke, B.N., and Wielgus, R.B. 2011. A spatially explicit, age/stage, metapopulation matrix model for wolf recovery in WA. Animal Conservation (In Prep).

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