National Elk Refuge officials say fall elk numbers were the lowest in 25 years, likely thanks to a combination of hunting pressure, good forage and mild weather.

At a time of year when it’s normal to see 3,000 elk congregating on the southern end of the National Elk Refuge, refuge biologist Eric Cole reported a high count of roughly 900 animals this week. Most of those animals came down out of the national forest east of the refuge Friday morning. Before that, the highest elk count this week was about 120 animals.

This week’s count comes after a season of elk counts that numbered well below the long-term average.

Cole said this year’s low numbers are mainly attributed to a limited-weapons south-unit hunt, which started Oct. 10 and ended Dec. 13. During that time, the hunt consistently pushed animals off the south end of the refuge and into the national forest or Grand Teton National Park.

The hunt’s effect was augmented by low snowfall amounts and plentiful forage. The snow/water equivalent is 63 percent of average for this time of year, and forage estimates were 20 percent above average.

“Elk are having no difficulty finding forage in locations other than the elk refuge,” Cole said. “The amount of forage that’s been consumed to date by elk and bison on the refuge has been negligible so far because we’ve had so few elk and bison during the fall period.”

By preserving forage, refuge managers hope to delay the onset of supplemental feeding, which congregates animals and can exacerbate the spread of diseases such as brucellosis, Cole said.

“The [start of feeding] is determined by the amount of forage that is available on the refuge,” Cole said. “That depends on how much forage we started with, the rate of consumption of that forage by elk and bison, and the snow conditions.”

Cole said snowfall is the one factor that could prompt wildlife managers to start feeding sooner than later.

“Everything’s pointing to a later than average start to the feeding season,” he said. “The wildcard is what happens with snow. El Nino, for this part of the Rockies, usually means below average precipitation for the winter.”

El Nino is characterized by unusually low temperatures over the equatorial Pacific, according to the National Oceanic and Atmospheric Administration. It’s expected to last until at least March.

Bison numbers also have remained low on the refuge, which, like elk, is attributed to good forage and low snowfall. A bison hunt on the refuge, which started in 2007, is probably also a factor, Cole said.

“We’ve had very low bison numbers on the south end of the refuge this year,” he said. “That was true last year until late winter. There’s more forage in Grand Teton National Park, so there is less incentive for them to move south. There’s also the possibility that the bison that remain in the population after three years of hunting them have learned that the refuge is not a safe place for them this time of the year.”

The refuge bison season is open until Jan. 3.