Study finds lethal methods to control wolves is ineffective

the Little River Band of Ottawa Indians (LRBOI) and the University of Wisconsin shows the current practice of killing wolves to protect livestock has done more harm than good.

The Little River Band of Ottawa Indians (LRBOI) and the University of Wisconsin report the current practice of killing wolves to protect livestock has done more harm than good. (News Advocate File Photo)

MANISTEE COUNTY — A study of Michigan’s wolf control methods finds the state should take a different approach to how it manages wolf attacks on livestock.

The published, peer-reviewed evaluation conducted by the Little River Band of Ottawa Indians (LRBOI) and the University of Wisconsin shows the current practice of killing wolves to protect livestock has done more harm than good.

“The Michigan Department of Natural Resource’s (DNR) practice of killing wolves to prevent predation on livestock doesn’t reduce the risk of attacks on livestock any more than non-lethal interventions,” said Ari M. Cornman of the LRBOI Natural Resources Department. “Furthermore, there is unexpected evidence of a side-effect where after killing one or more wolves on one property, neighboring properties in the surrounding area faced elevated risk. The research shows that killing wolves is not a solution to the problem of losing livestock.”

The DNR responds to wolf complaints in the Upper Peninsula, although it also contracts with a little-known Department of Agriculture bureau called Wildlife Services to kill wolves when they harm livestock.

“Coexistence in mixed-use landscape is challenging because some people perceive carnivores on the landscape as dangerous and because they sometimes threaten human property and safety,” said University of Wisconsin Dr. Adrian Treves, of the Carnivore Coexistence Lab. “Governments may respond by killing carnivores in an effort to prevent repeated conflicts or threats.”

But after analyzing the effectiveness of this strategy, the paper finds that the number of wolves killed did not predict the delay to recurrence of livestock losses at any spatial scale.

Cornman, Dr. Treves and University of Wisconsin PhD student Francisco J. Santiago Ávila analyzed the state of Michigan’s wolf control methods since 1998. According to the researchers, societies around the world place priority on preserving nature.

They recognize that meeting both goals has been challenging for millennia when it comes to large carnivores, such as gray wolves. Researchers accentuate there has never been a gold-standard experiment without bias to test, if killing carnivores will prevent future attacks on domestic animals.

The paper argues for raising the standards of science used for managing wildlife, endangered species and protecting domestic and wild animals. The research team evaluated state and federal government interventions following 230 independent verified wolf attacks on livestock in the Upper Peninsula of Michigan from 1998-2014.

Since 2003, the state contracted federal agents to live-trap and terminate wolves on or near livestock farms for up to several weeks after an incident.

Unlike a farmer shooting a predator whose jaws are clamped on a calf, federal trappers work far from the attack site and often long after an attack has occurred to capture and kill wolves. According to the research team, a properly science-based government program would have treated the trapping as an experiment and monitored the outcomes.

Before 2003 and intermittently from 2003 to 2014, the state sometimes also intervened with non-lethal methods of various sorts. Therefore, researchers investigated what they call a “silver-standard experiment” or case-control design to examine the risk of future attacks on livestock before and after the two treatments (lethal or non-lethal state intervention).

Researchers investigated whether killing wolves reduced the risk of a future attack on the original farm or in its vicinity, based on previous research suggesting that, after lethal intervention, remaining pack members may scatter and cause more conflicts.

Researchers conducted analyses at three spatial scales, from the one square mile section around a verified site of livestock loss up to the 320 square mile neighborhood of townships around it. The use of three spatial scales allowed them to measure recurrence of wolf attacks beyond the original sites of verified wolf attack (spill-over effects).

Researchers detected spill-over effects that they characterize as follows: a small percentage of farms with verified livestock losses did benefit from state-run wolf-killing, by suffering slightly fewer losses in the following months; but this was entirely compensated for by slightly elevated losses at a small number of neighboring farms in the same township.

The net benefit of killing wolves was zero.

Meanwhile, a small number of satisfied livestock owners might celebrate the success on their property, while their neighbors suddenly suffer more losses. If the farmers did not perceive the spill-over effects researchers detected, they might agree among themselves that the killing was helpful and more was needed.

The research shows that killing wolves is not a solution to the problem of losing livestock. Experiments with non-lethal methods in the very same region showed – with gold-standard evidence – that one can protect livestock without killing wolves.

Experiments run by Dr. Tom Gehring of Central Michigan University using livestock-guarding dogs and using fladry, a visual deterrent designed around flags hanging from fence-lines, proved effective during the short grazing seasons in the U.P. of Michigan. Other non-lethal methods have shown promise as well, though they have not yet been tested with gold-standard experiments with Great Lakes wolves.

Study further analyzed past scientific literature and found that there is no strong scientific support for killing wolves to protect livestock, at least using prevalent government methods.

The researchers conclude, based on their review of past studies, their findings and the new standards set by their research, that “no study in North America has yet proven with strong inference that killing wolves is effective in preventing future livestock losses.”

The research team argues for raising the standards of science used for managing wildlife, endangered species and protecting domestic and wild animals. Moreover, they point the way to eventual gold-standard experiments that should test government policy on wild animals.

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Posted by Ashlyn Korienek

Ashlyn is the cops & courts and city reporter for the Manistee News Advocate. You can reach her at (231) 398-3109 or akorienek@pioneergroup.com

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