JACKSON — Historically mild conditions on the valley floor have National Elk Refuge officials eyeing what could be the first winter without a supplemental feeding program in 37 years.
Where it catches the sun, the valley floor is completely brown during a time of year when the snowpack is customarily at its deepest.
And it’s not just the lowest-elevation areas in the refuge’s south side “snow shadow” that have only a skiff of snow or none at all — the Gros Ventre River bottoms are open, as are adjacent slopes on the Bridger-Teton National Forest.
The refuge’s 4,700 or so elk are acting accordingly, as they typically would in late March or April.
“They’re moving farther north,” Elk Refuge biologist Eric Cole said, “and completely of their own volition. They’re basically doing what elk are supposed to do — seeking forage where it’s available.”
Oddly, the snow-free Jackson Hole valley comes at the same time as an above-average snowpack at elevation — 117 percent of average, in terms of water weight — in Wyoming’s portion of the Snake River watershed.
Cole has no firsthand point of comparison for the unseasonably mild conditions that exist right now.
“This is a very unusual winter, and outside the realm of my experience in 20 years here,” he said. “We have zero snow at any of our monitoring sites. At the headquarters monitoring site, the average is 12 inches this time of year. This is usually when the snowpack depth peaks.”
Warmer-than-average temperatures increase the likelihood the Jackson elk and bison herds end up living off the landscape, sans supplemental alfalfa and hay.
“Usually if we have a low-snow year in Jackson Hole, temperatures are colder than average because it means inversions and dry, clear, cold weather,” Cole said. “Elk do respond to cold temperatures differently than they do to temperatures such as these. Their caloric demands are higher.”
National Weather Service data underscores how unseasonably warm it has been.
The average Jackson temp for the month of January was 22.2 degrees — nearly 5 degrees above the norm. The first two weeks of February have been even warmer: The average, 30.6 degrees, tops the historical average by more than 12 degrees.
Another factor that increases the odds of not feeding is a lack of bison, which are doled 2 1/2 times the amount of alfalfa per animal as elk. Most of the Jackson herd has lingered well to the north, and the highest on-refuge count this season is around 100 animals.
Typically, the refuge determines when to start its feeding program by measuring the amount of grasses accessible to elk and bison on important southern foraging areas. When the pound-per-acre estimate dips below 300 pounds, out go the alfalfa pellets.
This year, however, the gauge has less meaning, because wapiti and bison can chow down unencumbered by snow in places like the refuge’s northern aspen groves or near Mormon Row.
“We’re really in uncharted territory in terms of the significance of those measurements,” Cole said.
The approximately 11,000 animals that make up the Jackson Elk Herd are deviating from their normal winter whereabouts throughout their range. Up the Gros Ventre River drainage, home to three feedgrounds, there have been next to no elk drawn in by the prospect of hay. Many of the tracked animals that normally make their winter homes in the Gros Ventre have scattered. An abundance of wolves in the valley is one explanation why.
“We’ve got collars from the Gros Ventre scattered all over this country,” said Brad Hovinga, the Wyoming Game and Fish Department’s regional supervisor. “Dubois, Buffalo Valley, Green River, even one in the Hoback. They’re everywhere.”
It’s more like business as usual for the Fall Creek Elk Herd, denizens of the south end of Jackson Hole. Counting elk one-by-one during the third week of January, Game and Fish staff tallied more than 3,200 animals attending the South Park, Camp Creek, Horse Creek and Dog Creek feedgrounds.
This year, as always, Game and Fish staffers have coordinated with Cole and the refuge to monitor conditions.
“Normally when we hit the [300-pound] feeding threshold there’s nothing else available around the refuge, and this year there is,” Hovinga said. “So we plan to work with the refuge and take it day by day after that.
“Elk are happy, healthy,” he said, “and not looking like they’re getting restless or into conflict situations.”
There have been no reports of elk fleeing the refuge to the Spring Gulch area, he said. Such movements in the past have also triggered feeding.
Animals that summer in this area, bounded by Moose and Wilson, infrequently use Antelope Flats and the northeast portion of the refuge, where the low-snow terrain is sustaining thousands of elk that would usually be eating alfalfa.
“The big problem that we have is these short-distance migrants basically have little to no knowledge of those areas,” Cole said. “The question is, ‘Will these short-distance migrants utilize the forage in these areas when we run out on the south end of the refuge?’”
There have been nine winters in refuge’s 106-year history that the feeding trucks never ran. The last time was in 1981, an era when the animals that summered along Spring Gulch and the Snake River south of Grand Teton National Park numbered just a few hundred. Now there are thousands.
“So when you had a winter like this 35 years ago,” Cole said, “the odds of elk getting into trouble were significantly less.”
A blast of winter, of course, could quickly change conditions on the refuge and the behavior of elk — and prompt wildlife managers to start feeding. Feed trucks typically start laying down alfalfa lines the last week of January, but the feeding program has started as late Feb. 28.
In the meantime there are no frigid cold snaps or major snowstorms on the horizon.
“There’s nothing in the forecast to suggest that the situation is going to change,” Cole said.