By Cory Hatch, Jackson Hole, Wyo.
Jackson Hole elk migration habits have changed this year due in part to good forage, light snowfall and a new hunt on the south end of the National Elk Refuge, biologists say.
This year, animals lingered longer on so-called “transitional range” in Grand Teton National Park and subdivisions south of the park along the Snake River. Animals also spread out on the Bridger-Teton National Forest south and east of the refuge.
Typically, the refuge begins hosting thousands of animals in November, but only in recent weeks have elk migrated onto the south end of the refuge in such vast numbers.
The shift is good news for local wildlife managers, who implemented the new hunt in an effort to preserve winter forage on the refuge and delay the onset of winter feeding.
Researchers say crowded conditions on winter feed lines contribute to diseases such as brucellosis. The goal is to eventually reduce the number of elk on winter feed from about 8,000 to about 5,000 through hunting.
By Dec. 18, wildlife managers counted 3,600 elk on the south end of the refuge, and 70 percent of radio-collared elk likely to winter on the refuge had arrived.
That’s compared with last year, the first year of the south unit hunt, when 4,500 elk and 85 percent to 90 percent of radio-collared elk had arrived by mid-December.
In years past, some elk, especially those from Grand Teton National Park, used migration routes that bypassed hunt areas and allowed them to reach the south end of the refuge unscathed in the early fall. Before 2007, it was common for more than 4,000 elk to arrive by mid- to late November on the south end of the refuge, where they would linger and chomp on forage that managers thought would be best reserved for consumption later.
Instead, new hunting pressure on the south end caused animals that moved to the refuge early to return to the park, private land south of the park or the surrounding national forest land, National Elk Refuge biologist Eric Cole said.
Good forage and light snowfall also have helped keep elk in transitional range and off the refuge.
The new hunt on the refuge’s south end allowed only a few hunters into the field at a time and restricted them to short-range weapons like shotguns and bows. The weapons limitation was imposed to protect nearby homes from errant bullets.
“Animals remained in Grand Teton National Park on the west side of the Snake River longer than they had in recent years,” Cole said of the new hunt. “It caused animals to return to Grand Teton National Park, and it caused animals to move to the east around Crystal Butte, Curtis Canyon and Cache Creek. A large number of animals congregated in the private subdivision south of Grand Teton National Park along the Snake River.”
Another change that might have affected migration was a decision by the Wyoming Game and Fish Department to close some of the elk hunt seasons in areas adjacent to the north end of Grand Teton National Park earlier than usual.
“The hope was that by closing some of those elk seasons earlier, the elk would find security there and would not migrate to the refuge as early as they typically would,” Cole said.
As an example of how the changes are affecting elk movements, Cole pointed to data collected from an elk wearing a Global Positioning System collar.
“Around the last day of the refuge elk season, there was a pretty remarkable movement,” he said. “In just a couple of hours, an elk on the south unit in the morning … fled to the north spine of Jackson Peak above Goodwin Lake.”
Another elk, a female dubbed “elk number seven,” was captured and radio collared in 1991. Since then, the cow regularly had arrived on the refuge early and used a route that avoided hunters.
This year, elk number seven tried the same trick, but was disturbed by hunters and finally killed by one on the north end of the refuge.
“These are elk that had it figured out,” Cole said. “But that strategy isn’t working any more. That’s what our objective was.”
Based on radio-collar data, Cole figures that at least 17 percent of elk that summered in Grand Teton National Park were shot by hunters this year. Many of those were killed in the vicinity of Blacktail Butte, and most of those animals had been on the refuge at least once.
The south unit hunt targeted animals from the Grand Teton herd segment, which wildlife managers say is overpopulated compared with other parts of the Jackson Elk Herd, senior Grand Teton National Park wildlife biologist Steve Cain said.
“[The Grand Teton] segment and the segment that is on private land south of the park is quite a bit larger than we thought it was,” Cain said. “They are a difficult segment to get an adequate harvest on.”
“So far it looks like [the south end hunt] is doing what we hoped it would do,” Cain said. “I still think we’re behind the curve on reducing the number of elk that are on feed during the winter.”
Cain said he worries about the crowded feeding conditions on the refuge in winter and how they might affect disease transmission, especially since a moose with chronic wasting disease was detected in Star Valley earlier this year.
“With chronic wasting disease continuously marching closer and closer to this area, we get more and more concerned about concentrating animals on winter feed,” he said.
Now that the hunt has ended, Cole said he’s optimistic that this year’s feeding season could start late if the weather continues to cooperate.
“Forage this year was close to the long-term average – about 17,000 tons on the refuge,” he said. “Last year it was more like 12,000 tons. We’ve got approximately a foot of snow [on the refuge]. It’s powdery and it’s not limiting elk access to forage.”
Filed under: Elk, animal rights
