JACKSON, Wyo. — With about a month to go in 2010, the number of livestock killed by wolves in Wyoming is relatively low compared with 12-month totals starting in 2003, despite yearly increases in the wolf population.
As of mid-November, wolves have killed a total of 63 domestic livestock and horses, although some suspected depredations, injuries and deaths related to wolf activity are not included in the total. A total of 36 wolves have been killed for livestock depredations by wildlife managers so far.
The total of 63 animals to date is lower than yearly totals every year since 2003, when 43 livestock and horses were killed. That year, the number of wolves in Wyoming outside Grand Teton and Yellowstone national parks - roughly 90 - was less than half of the most recent U.S. Fish and Wildlife estimate of nearly 250 animals.
Depredations reached a peak in 2009, when 222 domestic pets and livestock, mostly sheep, were killed.
"In the very beginning, we tried to allow the wolf population to grow while still solving livestock problems," U.S. Fish and Wildlife Wyoming wolf recovery coordinator Mike Jimenez said. "The population has done very well. It has grown.
"Now we're addressing some of the chronic problems more aggressively," he said. "We issue permits for people to take wolves out on private property where we've had chronic problems year after year after year."
Even with more aggressive wolf management when livestock depredations occur, the number of wolves removed doesn't have an adverse impact on the wolf population, which has continued to grow at a rate of about 10 percent per year, Jimenez said.
Livestock depredations in the state are the result of the wolf population expanding its territory into agriculture lands, Jimenez said.
"When you get further out into (agriculture) land, you have a higher concentration of livestock and a lower concentration of big game animals," he said. "When you get into southwest Wyoming, there's a lot of domestic sheep. (Wolves) start killing livestock in those areas. They go after what's available and what's vulnerable."
Sheep are especially vulnerable because of their small size and lack of defenses. Of the 195 sheep killed in 2009, most were killed by three adult male wolves in the Bighorn Mountains.
Wolf packs that chronically attack livestock are targeted aggressively, Jimenez said. Since yearlings are most likely to cause problems, wildlife managers will sometimes attempt to leave the adults, the animals that define the pack's territory, alone.
"We try not to remove breeding adults at first," he said.