Earlier research showed little effect on cattle

By Ann McCreary

A new study underway in Okanogan County and northeast Washington will examine how the presence of wolves affects other wildlife species.

The study, scheduled to last at least five years, will assess the health of deer herds in the Loup Loup gray wolf pack territory, which includes the Methow Valley, and deer and elk herds in territory occupied by several wolf packs in the northeast part of Washington.

The Washington Department of Fish and Wildlife (WDFW) and the University of Washington (UW) are conducting the study, to determine how eight years of growth in the state’s wolf population is impacting deer and elk.

“The experience in other western states shows that wolves and other predators may affect the size and behavior of deer and elk herds,” said Eric Gardner, head of the WDFW Wildlife Program. 

“We want a closer look at the situation here in Washington State as our own wolf population continues to grow,” Gardner said.

Researchers will also examine the response to wolves by other predators, especially cougars, Gardner said.

A different study, now in its third year, has been conducted by Washington State University (WSU) to examine the interactions between wolves and livestock.

One part of that study, which included the Lookout and Loup Loup packs in the Methow Valley, focused on the extent of wolf depredations on livestock. It concluded that attacks by wolves on livestock were rare and losses to ranchers were very low. 

As of June 2016, WDFW had confirmed the presence of 19 wolf packs and at least 90 wolves in Washington. The Lookout Pack, first identified in 2008, was the first gray wolf pack observed in Washington in more than 30 years.

The Lookout Pack had five members in 2008 and grew to 10 members, but was decimated by poaching, leaving only three members by 2009. Biologists believe there may be a wolf or two in the former Lookout Pack territory, but the pack appears to have disappeared.

Collaring critters

For the study launched this year by WDFW and UW, research scientists and field biologists began capturing deer, elk and cougars in the two study areas in January and fitting them with radio collars to monitor their movements.

Capture techniques include trapping animals using bait, steering them into nets, and darting them from helicopters with immobilization drugs.

As of mid-February, researchers had collared 19 mule deer and five cougars in and around the Methow Valley, said John Pierce, chief scientist for the WDFW Wildlife Program.

The deer were collared by herding them into “drive nets,” which are mesh nets that collapse around the deer when the deer run into them.

“They get entangled, and a group [of researchers] on the ground is ready to tackle and collar them,” Pierce said.  He said about 20-30 wildlife staff helped with the project.

The researchers used dogs to track and tree cougars, which are then darted with an immobilization drug, brought down from the tree and collared.

The goal is to collar 100 mule deer and 10 cougars in the Loup Loup Pack territory that extends from the Methow Valley to the Okanogan Valley.  Most captures are done in winter, and researchers will continue working next winter to reach the goal, Pierce said.

In the northeast Washington study area, researchers hope to place collars on 65 white-tailed deer, 50 elk and 10 cougars. That study area includes parts of Ferry, Stevens and Pend Oreille counties, with about eight wolf packs.

The Loup Loup pack has three collared wolves that will be monitored as part of the research, Pierce said. Researchers want to maintain collars on at least two wolves in each pack within the study areas, Pierce said.

“More collars mean we feel more confident in the results” of the study, Pierce said.

UW students will join WDFW research scientists and field biologists to monitor radio-collared animals and track their movements, distribution, habitat use, diet, reproduction and survival, Pierce said.

Cougars will be monitored to learn about changes in social behavior, prey selection and predation rates in areas where wolves are also present, he said.

“This study concentrates on multiple use lands used by people for activities such as logging, livestock ranching and hunting,” Pierce said.

“In that way it differs from most other studies on the impact of wolves, which tend to be conducted in national parks and other protected areas,” he said.

The study will also look at cougar behavior in urban interface areas, Pierce said.

Researchers will periodically develop and share progress reports about the study over the next five years.

Funding for the five-year study includes $400,000 from a 2015 state legislative appropriation, $450,000 in federal funds and $150,000 of WDFW funds. The UW also secured about $900,000 in National Science Foundation grant funds for the project.

Wolves and livestock

The WSU study that began in 2014 focuses on the interactions of wolves and livestock. Research was conducted in Lookout Pack territory in 2014 and 2015, and in the Loup Loup Pack territory in 2016. The study was also conducted in other parts of the state where wolves and livestock occupy the same areas.

A portion of the study that examined cattle deaths caused by wolves has been completed, and found that “overall [livestock] depredation losses were very low in wolf-occupied areas of Washington.”

A research thesis by Jeffrey Brown, available on WSU’s online library, estimated losses of livestock in wolf-occupied areas. Brown radio-tagged 588 calves in 10 cattle herds (including some Methow Valley herds) and 176 sheep in one flock to examine the cause of mortalities in the animals over two grazing seasons.

“I detected one sheep and one calf death, but no wolf kills during telemetry monitoring, despite all herds having spatial overlap with wolves,” Brown said in the abstract of his master’s thesis.

“Our results indicated that losses due to wolves were not above 0.81 percent for cattle or 1.6 percent for sheep within pack territories in the Washington population,” Brown wrote.

“Though acute impacts of wolf depredations can occur and be detrimental to individual livestock operators, our results suggest that those severe events were rare and that overall depredation losses were very low in wolf-occupied areas of Washington,” Brown said.

The WSU study, which is funded through $1.2 million in legislative appropriations, is also examining the kinds of animals killed and eaten by wolves, and how the presence of wolves affects livestock health and behavior.

Gabe Spence, a WSU graduate student, collected data on wolf hunting and diet by putting radio collars on wolves in areas where livestock are grazed on public lands, including the Methow Valley.

He and fellow researchers used location data from collared wolves in five packs each summer to locate areas of hunting activity, hike into those areas, and record what they found. Spence said he is still analyzing data and writing his thesis.

“My results show that most wolf packs in Washington subsist primarily on wild food, chiefly deer, moose and elk, even during the grazing season,” Spence said.

“Rarely, wolves will switch from using wildlife as food to using livestock as their primary food source. When this happens wolves hunt and feed themselves with livestock with the same frequency and in the same manner in which they use wild food,” Spence said.

“One thing that did surprise me was how much some packs scavenge for food. It seems that if carrion is available, wolves will readily use it, even in the summertime,” he said.

“Our goal with this project is to conduct sound science and use what we learn to help farmers and ranchers as well as wildlife communities,” Spence said.

“There are often no easy answers to help create this balance, so it can be challenging at times to remain positive and continue to search for solutions.”