Yellowstone National Park

Yellowstone National Park

Wyoming wolf numbers rise outside Yellowstone; Population decline in the park was anticipated, biologist says

December 16, 2009, 9:47 am

Wyoming’s wolf population is thriving and growing in most of the state, despite continuing declines among Yellowstone National Park wolves, a U.S. Fish and Wildlife Service biologist says.

Wyoming’s wolf population – animals in the Equality State whose home ranges are outside Yellowstone – grew from 178 animals, 30 packs and 16 breeding pairs last year to an estimated 200 in 30 packs with between 19 and 21 breeding pairs this year. The overall increase is 12 percent, although year-end numbers won’t be calculated for some time.

USA Today recently reported that the decline in Yellowstone can partly be attributed to the loss of federal protections for the species in Idaho and Montana. Wyoming wolves remain under the protection of the Endangered Species Act.

Inside Yellowstone, the population declined from 171 wolves in 2007 to 124 wolves in 2008 and 116 wolves this year. The change marks a 32 percent decline in three years, a 6 percent decline this year.

While Montana hunters did kill four wolves from the Cottonwood Pack, which inhabits a territory on both sides of the boundary between Montana and the park, the U.S. Fish and Wildlife Service Wyoming wolf recovery coordinator, Mike Jimenez, said Yellowstone’s population decline has more to do with natural processes.

“The wolf populations in Montana, Idaho and Wyoming are all expanding and doing very well,” he said. “The population drop in Yellowstone has been anticipated from day one and is from natural causes.”

Idaho had 846 wolves at the end of 2008 and 113 have been killed so far in its hunting season, according to state information. Montana had 500 wolves at the beginning of the year and 74 had been killed when hunting closed Nov. 17, the state wildlife agency said.

Researchers think a significant number of Yellowstone’s wolf deaths come from wolves killing other wolves over territory or prey.

“Wolves in Yellowstone are a small [proportion] of the northern Rocky Mountain population,” Jimenez said. “It is going through a small equilibrium change, and that is no surprise. The concern about hunting wolves and delisting is far more politics and drama.”

Louisa Willcox, a senior wildlife advocate for the Natural Resources Defense Council, agreed that most of the decline in Yellowstone is likely due to natural causes. Wildlife managers, however, underplay the significance of the deaths in the Cottonwood Pack.

“Those were highly productive wolves that they were hunting,” she said.

But the bigger problem is state laws that allow too many wolves to be killed, Willcox said.

“Prey and predators find an equilibrium,” she said. “Things are going to go up and down.

“We have a dynamic system, and you need to buffer that system, realizing that there are periodically big swings,” she said. “We should be adopting a precautionary principle when it comes to wolves.”

This year, 30 wolves were killed in Wyoming outside Yellowstone for attacking livestock. Another five wolf deaths are attributed to unknown causes or are under investigation.

In 2008, 79 wolves were killed, 46 for attacking livestock and 11 in a hunt in Wyoming when the animals briefly lost federal protection. Eight more deaths are under investigation, eight wolves died from unknown causes, three from natural causes and two from vehicle strikes, Jimenez said.

While sheep depredations in the state skyrocketed this year, from 26 in 2008 to 195, a more than six-fold increase, cattle depredations have dropped every year since 2006. They went from 123 in 2006 to 20 this year, a drop of 83 percent. Wolves also killed seven dogs this year.

The bulk of this year’s sheep depredations came from three packs, one in the Bighorn Mountains, one near Dog Creek south of Jackson and one near Rock Creek north of Pinedale, Jimenez said. All three packs arrived in their respective areas in the last couple of years, and most of the wolves were killed by U.S. Wildlife Services for the depredations, Jimenez said.

Not all wolves that live in areas with livestock are problems, he said.

“There’s a couple places where we’ve had wolves, year after year, cause problems and we respond very aggressively,” he said. Some wolves, however, “don’t seem to be as cattle-oriented as some of the other packs. We ... leave them there because they maintain that space. They keep other wolves from re-establishing in there.”

“Wolf behavior is so varied, it’s tough to say this worked so let’s do that again,” Jimenez said. “We know that older wolves probably aren’t the ones responsible for the killing, but the ones who define those pack territories are the older ones. We’ve tried to eliminate the ones that are causing the problem.”

In the Jackson area, Jimenez said there are currently four full-time packs and one that spends part of the year here. The Phantom Springs Pack lives in Grand Teton National Park and likely consists of four adults and four pups. The Pinnacle Peak Pack, which consists of roughly four adults and six pups, spends summer, spring and part of the winter on the National Elk Refuge, and the fall and early winter outside Bondurant.

The Antelope Pack probably consists of six adults and one female and lives in an area near the northern part of the National Elk Refuge and the southeast flank of Grand Teton National Park.

Those wolves “had bad mange in the pack,” Jimenez said. “Maybe one pup survived, but the rest of them did not.”

Just to the north of the Antelope Pack’s territory, the Buffalo Pack probably had a double litter this year, the result of two females breeding with a single male. Of the 17 to 20 wolves in the pack, about 13 are pups.

“Life is good” for the Buffalo Pack, Jimenez said. “There’s lots of elk and there’s lots of habitat. In areas where they’re not hunted, packs get larger and hang around a lot longer. Wolves respond to whatever you hand them.”

The Pacific Creek Pack, which lives in the Buffalo Valley and the Teton Wilderness, consists of about nine adults and four females. And finally, the Chagrin River Pack consists of eight to 10 wolves that live on the west side of the Tetons near Alta and Victor and Driggs, Idaho.

The Huckleberry Pack, which used to live in Grand Teton National Park, is gone now, with some of its members likely folded into the Phantom Springs Pack.