Great Lakes Article:

Researchers target areas where wolves are most likely to attack livestock
By Susanne Quick
Milwaukee Journal Sentinel
02/27/04

If you knew you were more than twice as likely to get roughed up in front of doorways that were painted blue rather than red or green, you'd probably avoid those stoops altogether, or at least get your police to patrol them.

In a way, identifying such danger zones is what a team of Wisconsin, Minnesota and New York scientists have tried to do - except, instead of targeting high-crime doorsteps, the scientists have mapped areas where wolves are most likely to attack livestock in the upper Great Lakes region.

And they hope this research will enable state and federal wildlife agencies to focus their energy on potential hot spots - allowing them to prevent and respond more quickly to livestock killings, said Adrian Treves, lead author and researcher at the Wildlife Conservation Society in the Bronx, N.Y.

Their work appears in the most recent edition of the journal Conservation Biology.

The loss of livestock to wolves in Wisconsin and Minnesota has caused a lot of grief, anger and frustration among livestock farmers who live in established wolf ranges.

According to the Wisconsin Department of Natural Resources, wolves killed 20 cattle and 24 sheep on more than a dozen farms in the state last year. They also killed one game farm deer and six hunting dogs in the same period.

In Minnesota, where the wolf population is about seven times larger than in Wisconsin, wolf numbers, trappings and depredations were down last year - the result of the nasty skin disease mange that has swept through the population. Minnesota has nearly 2,500 wolves, and Wisconsin has about 350.

But the livestock situation is likely to get worse, particularly in Wisconsin, where the wolf population is increasing and its range is spreading.

It is this fear, with a splash of anger over lost farm animals, that has livestock farmers calling for wolf numbers to be decreased.

And it is the acknowledgment that things will likely get worse that has wildlife experts and conservationists looking for ways to prevent, or at least soften, the inevitable increase in domestic animals killed.

In search of a solution

According to Treves' and his colleagues' work, wolf management is difficult. Outright killing of wolves is something they hesitate to recommend, believing it can undermine endangered-species protections and incite criticism from groups other than livestock farmers.

But, they know doing nothing is not a solution, either.

Indeed, a recent study by Treves and his wife, Lisa Naughton-Treves, a professor of geography at the University of Wisconsin-Madison, showed that 36.5% of northern Wisconsin residents wanted the state's wolf population maintained and 13% wanted it expanded, while a similar percentage wanted the population reduced (33.1%) or eliminated (17.4%).

These numbers leave management agencies in a predicament: Anything they do is going to make somebody unhappy.

So Treves, Naughton-Treves, Adrian Wydeven, a wolf biologist with the DNR, and others searched for a more efficient method of management, one that would help state and federal agencies anticipate and pinpoint future wolf attacks on livestock.

Currently, most of the wolf management zone in Wisconsin is in the northern third of the state. Minnesota has two zones - one with wolves and one without.

These vast expanses of land make it difficult for state and federal agencies to monitor wolves, which can make management ineffective, expensive and diluted.

By narrowing the zones to towns, Treves and his colleagues believe they will enable agencies to manage the wolf problem better.

So, to create a new, focused system, the researchers scrounged up data on wolf attacks on livestock and reviewed the locations. Looking at 975 verified sites of livestock killings by wolves in Wisconsin and Minnesota between 1976 and 2000, they analyzed each site.

They asked a series of questions: Was it in a prairie? If so, how big? Was it in a crop field? Near conifer woodlands? Open water? Wetlands? In a town?

Based on the localities of each of these incidents - and the commonalities, if any - they tried to predict where farmers would find future fatalities.

They discovered that wolf attacks tend to take place in towns composed of lots of pasture with dense deer populations but also have low proportions of cropland, coniferous forest, herbaceous wetlands and open water.

The number of roads also seemed to be a factor: Fewer wolf problems were reported in areas with lots of roads.

Entering this data into statewide maps, they were able to pinpoint areas that are at high risk. Some of these areas don't have settled populations of wolves anywhere near them, but, if wolf populations continue to spread, those areas could see some trouble.

Farm country prime target

One such place includes the livestock farms of southwestern Wisconsin. The geography in this region could make them prime targets for killings by wolves, if they were to get there.

But this area may be a bit insulated because most of the cattle are dairy, Treves said.

That's because dairy cows are generally kept close to human-inhabited areas such as farmhouses.

The cattle most at risk, said Wydeven, are those that stray from frequent human supervision.

"The best method for preventing wolf depredations" is to have a person watching the herd 24 hours a day, Treves said.

Other methods to keep wolves at bay - such as fences and guard dogs - are not as effective, Wydeven said.

Fences can work, said Eric Koens, a livestock farmer in Bruce and a director with the Wisconsin Cattlemen's Association, though they have to be at least 8 feet highand buried at least 2 feet in the ground to keep the wolves from digging through.

And the maintenance would be formidable, he said.

David Mech, a senior research scientist with the U.S. Geological Survey and a renowned wolf biologist, agrees.

"We just don't know of anything that would work as a panacea" to prevent wolf depredations, said Mech, who was not involved with the research.

"Where there are wolf and livestock, living side by side, there's a good chance that at some point, they'll prey on livestock," he said.

Treves and Wydeven disagree. They say there are good packs and bad packs. Most wolf packs can live by cattle or sheep farms for years and never attack. But there are a few that do.

Although Wisconsin DNR officials have shown interest in the map, they'd like to know if its powers of prediction hold true before they start using it, Treves said.

The researchers will collect data on killings since 2000 and see how it fits with the map's predictions.

If the map predicted accurately, Koens and his fellow farmers will, at the very least, be able to take preventive measures if they are unfortunate enough to be in one of the hot spots.