Peer-Reviewed Research

"Predator control should not be a shot in the dark"

September 1, 2016

 "This review shows that state and federal agencies are relying on bad science and bad research to justify their use of lethal predator control programs...This research calls for a moratorium on lethal predator control policies until researchers adopt higher testing standards."  Click here for short video explaining the findings.

"Blood does not buy goodwill: Allowing culling increases poaching of a large carnivore"

May 11, 2016

by Guillaume Chapron, Adrian Treves

17-year study (1995-2012) suggests gov't-sponsored killing sends negative signals about the value of wolves and increases inclination to poach wolves (see Youtube video).   Examples of negative signals sent out by WI's state agency over the last 4 years include:


  • 2013 lowering of license fees from $100 to $47 (resident)
  • Going over quota in wolf hunts
  • Not enforcing caution areas (allowing repeated dog & wolf conflicts, depredations & payments)
  • Hound dogs on wolves (training & hunting)
  • No required carcass ID following dogs on wolves in hunt
  • Did not honor tribes under quota rules 
  • Disbanded Wolf Stakeholder committee representative of all interests

"Inclination to illegally kill wolves persists in Wisconsin, study finds"

by the Nelson Institute for Environmental Studies; UW-Madison


August 7, 2015

This research suggests that killing wolves (government or regulated hunting) is not an effective method to increasing tolerance.  The research may be helpful to inform other methods of interventions that will successfully  increase tolerance.



Photo credit: Flickr
Photo credit: Flickr

"Tolerance of Wolves in Wisconsin continues to decline"

by Hogberg et al.

An extensive, long-term UW-Madison study showed a decrease in people's tolerance of wolves extending thru the legislated wolf hunt of 2013.  Increasing tolerance of wolves via a wolf hunt was promoted by the state agency, hunting groups and legislators as justification for a wolf hunt.  Alternative strategies were suggested including other research showing public education promoting benefits of carnivores as critical.  The study surveyed the same individuals from 2001 thru 2013.  


Photo credit: Wikimedia Commons
Photo credit: Wikimedia Commons

"Study looks at biofences for managing wolves"

by Christine Anhalt


Among many things, this study suggests that rendezvous sites are a "critical resource" for wolves and also conveys the need for the protection of these sites in state agency wolf management plans.




"Landscape Predictors of Wolf attacks on bear hunting dogs in Wisconsin"

March 2015

Research (pdf link) shows core habitat for wolves represents the highest risk to dogs in Wisconsin.  Since hunters "voluntarily" place their dogs at risk, this research proposes an alternative compensation model based on the fact that wildlife is intended for public lands and with that comes an accepted level of risk.  Some proposed recommendations: compensation based on habitat which determines level of risk; public vs. private land; Reduction of bear-baiting (WI-141 days vs. MN-14 days); .  Livestock compensations have been adjusted recently; hound depredations have not and they are individually the most costly. 


"In Wisconsin, as in many other states and countries, wolves are now a part of the landscape and with this comes responsibility, for both the government (under the public-trust doctrine) and the private individual, to mitigate conflicts with wolves."


Photo credit: Flickr
Photo credit: Flickr

"Utility of livestock- protection dogs for deterring wildlife from livestock farms"

by Gehring et al.

Great Lakes region livestock producers face unique challenges not only from predators but wildlife such as ungulates that can transfer infectious diseases such as bovine tuberculosis to their cattle as well.  The research results "provided evidence that LPDs are an effective non-lethal management tool for deterring wolves,coyotes and deer from livestock pastures."

Utility of livestock protection dogs for deterring wildlife from livestock farms
Gehring et al LPD's.pdf
Adobe Acrobat Document 198.4 KB
Photo credit: Wikimedia Commons
Photo credit: Wikimedia Commons

"Black Bear conflicts and the Effects of Current Conflict Mitigation Strategies in Wisconsin"


Zachary K. Voyles


"...there is no evidence to suggest that increased hunter take has reduced complaints in Wisconsin...Wisconsin’s bear harvest is not designed at a spatial scale on par with nuisance bears or bear complaints. "  Voyles suggests using community members  to promote nonlethal measures such as removal of bird feeders, bear-proof containers and promotion of coexistence in general.  

In the end, there is no evidence/research to suggest that killing bears is nothing more than a recreational activity that orphans bear cubs with little chance for survival.

Building Tolerance for bears: A Communications Experiment
Peer-reviewed research illustrates public education increases tolerance for large carnivores such as bears. Ohio survey set out to determine what factors determine people's acceptance of bears. Four different fact sheets were distributed to a large group of people; A very surprising and intriguing study.
Slagle et al. bears.pdf
Adobe Acrobat Document 114.6 KB


"Landscape predictors of wolf attack on bear-hunting dogs"
Since hunters "voluntarily" place their dogs at risk, this research proposes an alternative compensation model based on the fact that wildlife is intended for public lands and with that comes an accepted level of risk.
Olson et al; Landscape predictors of wol
Adobe Acrobat Document 1'017.7 KB


Photo credit:
Photo credit:

January 2015

"Tolerance of Wolves in Wisconsin: A mixed methods examination of policy effects on attitudes and behavioral inclinations"

 2001-2012: Mail surveys and focus groups consisting of bear hunters, deer hunters and livestock owners illustrated that wolf hunts (legalized lethal control) was not found to increase tolerance.


Photo credit: Wisconsin DNR
Photo credit: Wisconsin DNR

January 5, 2015

"Study finds deer have caused extreme changes in Wisconsin's ecosystem." 

Wisconsin-Madison botany professor stated, "Those habitat conditions are deteriorating. It’s a clear signal that we should back off on the density of deer we maintain.”  Less wildflowers and regrowth of trees along with a link to decline in songbirds suggested and harm to soil.  Link here for research:

"Long-Term Regional Shifts in Plant Community Composition Are Largely Explained by Local Deer Impact Experiments"



"Removing protections for Wolves and the future of the Endangered Species Act"

Removing protections for wolves not only ignores scientific research but will ultimately strip protections for all species and their habitat.


"People and large carnivores can live together, study suggests"

50 European wildlife biologists suggest that positive public attitude and support along with strong protections illustrate that "...large carnivores can coexist with large numbers of people…"


25 December 2014

"Challenge the abuse of science in setting policy"

"With increasing calls to make policy science-based, political abuse is likely to become more common…"


03 December 2014; "Effects of Wolf mortality on livestock depredations" "Lethal control of wolves appears to be related to increased depredations in a larger area the following year…"


Photo Credit: Wisconsin DNR
Photo Credit: Wisconsin DNR
"The potential physiological effects of substantial, human-caused mortality suggest that hunting could be causing changes in reproductive structure and breeding strategy as well as chronic stress."
Heavily hunted wolves have higher stress
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September 2014

"Pendulum swings in wolf…."

"To our knowledge, this research provides the first demonstrated link between illegal wildlife killing (in Wisconsin) and management authority under the Endangered Species Act, and suggests that illegal behavior may be moderated with responsible and effective wildlife management programs.  We recommend states avoid prescriptive harvest legislation, and we suggest a more incremental shift from federal to state management authority." (see Pdf doc. below)

"Pendulum swings in wolf management led to conflict, illegal kills and a legislated wolf hunt"; September 2014, Conservation Letters
Olson etal. September 2014_pdf.pdf
Adobe Acrobat Document 679.7 KB


Link here for excellent audio by Dr. Adrian Treves clarifying purpose of biologists' letters (below)

6 Biologists respond to 7 October 2014 Region 3 letter
"The USF&WS does have the regulatory authority to correct the situation and enforce adequate, existing regulatory mechanisms by the States.
USFWS 15 October 2014; 6 biologists' res
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USFWS 7 October 2015 response letter to Dr. Treves et al.
USFWS 10:7 letter to Dr. Treves.pdf
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Scientific concerns regarding Wisconsin's Gray Wolf Population
Three concerns and remedies recommended by five scientists including Wisconsin's Post-Delisting Monitoring report; unregulated training of hounds on wolves & hounds used in wolf hunt; monitoring methods
Treves' USFWS letter Aug 25.pdf
Adobe Acrobat Document 820.6 KB
Recolonizing Wolves trigger a trophic cascade in Wisconsin
Wolf recovery in Wisconsin critical to ecosystem restoration.
Trophic Cascade callanetal2013-1.pdf
Adobe Acrobat Document 2.3 MB
Trophic Cascades in a Multicausal World: Isle Royale and Yellowstone; Peterson, Vucetich, Bump, Smith; 22 September 2014.
Is it top down or is it bottom up? The complexities of cascading impacts on ecosystems. It's not just about the wolf.
Trophic Cascades 2014.pdf
Adobe Acrobat Document 658.5 KB

"Trophic Cascades from Wolves to Grizzly Bears in Yellowstone", 2013; Ripple, Beschhta, Fortin & Robbins.  Rare evidence that shows berries as food source for grizzly bears increased following the introduction of Gray Wolves in Yellowstone:  Wolves keep elk moving which allows bushes to grow to produce berries.  

Tolerance for Predatory Wildlife; Adrian Treves & Jeremy Bruskotter (2014)
It is suggested here that both social factors and government-sanctioned killing of predators is more strongly linked to predator poaching than other previously held views.
Tolerance for Predatory Wildlife; Treves
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Hunters as Stewards of Wolves in Wisconsin and the Northern Rocky Mountains, USA
"In sum, governments cannot assume hunters will support the conservation of wolves simply because they did so in the past for other game."
Adobe Acrobat Document 95.6 KB

10 January 2014

"Status and Ecological Effects of the World's Largest Carnivores";

William J. Ripple et al.

"Large carnivores face enormous threats that have caused massive declines in their populations and ...

Wildlife: Denali Wolf packs hammered by hunting“We noticed that human-caused mortality rates were highest during the winter and spring, which correspond to the pre-breeding and breeding seasons for wolves,” said Laura Prugh, co-author and wildlife ecologist at the UAF Institute of Arctic Biologist. “Harvest may lower the odds of pack survival because of this timing, especially when pack sizes are small.”..."Wolf advocates say lack of Denali buffer has economic consequences"; 07/13/2014.  (see following pdf for peer-reviewed research pertaining to this article regarding impacts of breeder loss).

Impacts of breeder loss on social structure, reproduction and population growth in a social canid
Impacts of breeder loss on social struct
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Density Dependent Instraspecific aggression regulates survival in Northern Yellowstone Wolves, Journal of Animal Ecology; Cubaynes, MacNulty,Stahler, Quimby, Smith, Coulson (May 2014): 13-year study suggests wolves regulate their numbers; when population increases wolf pack mortality increases.

Fauna & Flora International (May 2014);  "Dead or Alive: Comparing costs and benefits of lethal and non-lethal human-wildlife conflict mitigation on livestock farms"; McManus, Dickman, Gaynor, Smuts, Macdonald.  "Non-lethal measures were cheaper than lethal control on 91% of the farms in the first year of implementation."

"Reducing numbers of one carnivore species indirectly leads to extinction of others" 04/09/2014 by for Biodiversity's Sake, originally published in journal of Ecology Letters, 02/28/2013.

Biology Letters; Krumm, Conner, Hobbs, Hunter, Miller, "Mountain lions prey selectively on prion-infected mule deer"; (October 2009) "mountain lions were selecting for infected individuals when they targeted adult deer...predators like wolves and coyotes select prey disproportionately if they appear impaired by malnutrition,age or disease."


American Black Bear nuisance complaints and hunter take
Evidence does not show that hunting of bear will minimize nuisance complaints in the future.
Treves' Hunting Bears.pdf
Adobe Acrobat Document 388.0 KB


Evaluating the scientific soundness of plans for harvesting wolves to manage depredations in Michigan
Vucetich, J.A., J.T. Bruskotter, R.O. Peterson, A. Treves, T. Van Deelen, and A.M. Cornman. 2013 Little River Band of Ottawa Indians Natural Reosurces Report No. 2013-3.
Michigan's state agency claims that killing wolves is for the purpose of depredation management, but this has no scientific support.
Vucetich's 2013 Wolf hunting & depredati
Adobe Acrobat Document 742.9 KB
Biological Conservation, Dec. 2013: Saving large carnivores, but losing the apex predator?
Research suggests exploitation of large carnivores may drastically decrease their impacts on trophic systems while also affecting their evolution as a species.
Saving large carnivores, but losing the
Adobe Acrobat Document 739.2 KB
Hunting for Large Carnivore Conservation: Adrian Treves; Carnivore Coexistence Lab
Claims that public hunting of carnivores eliminates property damage while also conserving their population lacks scientific support.
Treves' Hunting Carnivores.pdf
Adobe Acrobat Document 160.6 KB
"It takes a village"
"It takes a village"

"Final Review of Proposed Rule regarding Wolves" (January 2014) pdf

USFWS-appointed biologists unanimously conclude flawed process in delisting of wolves.

Public Attitudes towards Wolves in WI - 2013 Survey Report
Study of WI residents in wolf and non-wolf range over a period of 12 years.
Treves' 2013 Wolf Tolerance Survey Repor
Adobe Acrobat Document 1.7 MB


"Effects of Sport Hunting on Cougar Population, Community and Landscape Ecology"; 15-yr. research out of Washington's Large Carnivore Conservation Lab -  as hunting increases so do cougar conflicts.