Biologists tallied 5,000 elk and the bulk of Jackson Hole’s bison herd Friday on the National Elk Refuge, but managers have thus far been able to forgo supplemental feeding.

The 600 bison counted on the refuge didn’t emerge until late this week, refuge biologist Eric Cole said.

“We have had a late migration to the refuge,” Cole said, “and that has likely delayed the need to begin supplemental feeding.”

A number of factors — including animal counts, snow depth and forage production — go into the decision to begin feeding.

On Friday, snow depths at the refuge’s south end averaged 5 to 10 inches, and accessible forage was considered adequate, Cole said. The next forage assessment and animal count is scheduled for Monday.

Cole didn’t speculate when supplemental feed would be necessary, but, he said, “I would say there is a very high probability that we will be feeding this winter.

“The last time that we did not feed at all is 1981,” he said, “and there were hardly any bison in Jackson Hole then.”

Over the past decade, the average start date for feeding has been Jan. 26.

When gauging whether to start feeding, Cole said refuge managers don’t look for changes in elk and bison behavior but rather try to keep them from moving off the refuge. When that happens, elk often head into the Spring Gulch area.

A 15-year multi-agency bison and elk management plan mandates that the refuge decrease reliance on artificial feeding.

One Jackson Hole critic of the feeding program called for more tolerance and infrastructure for wandering elk.

“One of the things that the Fish and Wildlife Service should do is help livestock owners with elk-proof fences,” said Lloyd Dorsey, the Greater Yellowstone Coalition’s Wyoming representative. “It would enable the Fish and Wildlife Service to stall artificial feeding for a longer period of time and it would allow for the careful phase-out of artificial feeding on the elk refuge.”