Conflicting scientific reports could play a role in a recent lawsuit challenging supplemental feeding on the National Elk Refuge as different groups point to conflicting forecasts on whether Jackson Hole’s elk could survive on natural forage alone.

Conservation groups filed the complaint June 10 in U.S. district court in Washington, D.C. The groups are challenging the Bison and Elk Management Plan for the elk refuge that the U.S. Fish and Wildlife Service and the National Park Service released last summer.

The groups say the plan violates the National Environmental Policy Act and the National Wildlife Refuge System Improvement Act, encourages disease and harms habitat.

With the plan, wildlife managers aim to reduce the number of elk wintering on the refuge from between 6,000 and 8,000 animals to 5,000 animals and the number of bison from 1,200 to 500 through hunting. The elk and bison plan would attempt to reduce the need for supplemental feeding by improving habitat, but the plan does not end supplemental feeding altogether.

Last week, feeding proponents with Sportsmen for Fish and Wildlife pointed to a paper by retired biologist Garvice Roby, a researcher who spent 20 years studying Jackson Hole elk. The report predicts that ending supplemental feed would “result in less than 3,000 to 4,000 elk on the National Elk Refuge and 5,800 total elk surviving in deep winter snow.”

The report further concludes that the end of supplemental feeding would cause at minimum a 57 percent reduction in current elk numbers.

This winter, Wyoming Game and Fish Department biologists estimated a total of 12,370 elk in the Jackson elk herd, 11 percent more than the Wyoming Game and Fish Commission’s stated objective for the herd of 11,000 animals. Roughly 8,000 animals spent the winter on the National Elk Refuge.

According to a Sportsmen for Fish and Wildlife summary of the Roby report, an end to supplemental feeding would “cause elk and bison to seek forage on private lands, the same lands currently used to winter domestic livestock. Large scale brucellosis transmission will be inevitable.”

 
Both sides cite disease risk

Authors of the bison and elk plan relied heavily on the Hobbs Model, named after Dr. N. Thompson Hobbs, an ecology professor at Colorado State University. The plan states that without supplemental feeding, “the Jackson elk herd would have an estimated 9,300 to 11,000 elk, and fewer elk would winter on the refuge.”

Further, “the risk of a nonendemic infectious disease quickly spreading through the population or having major adverse impacts to elk survival would be among the lowest of all the alternatives because of eliminating contact associated with the feed lines, reduced numbers and increased dispersion.”

A summary of the Hobbs Model states that, during an average winter, “500 bison and 16,000 elk can find forage in the Greater Teton ecosystem without incurring forage deficits and 5,000 elk can forage on the [refuge] without incurring deficits.”

However, “when drought precedes deep-snow winters, forage deficits are extreme. High mortality of elk in the absence of supplemental feeding may be experienced in these winters.”

The Greater Yellowstone Coalition has released its own analysis of forage availability in the Gros Ventre drainage, one area that conservation groups say is underutilized by elk. Earthjustice filed the lawsuit for the Greater Yellowstone Coalition, Defenders of Wildlife, the Jackson Hole Conservation Alliance, the National Wildlife Refuge Association and the Wyoming Outdoor Council.

The 2005 report states that historically, more than 4,500 elk wintered in the Gros Ventre drainage. Using a conservative estimate of available forage, it said, between 4,419 and 6,628 elk can winter naturally on between 33 percent and 55 percent of 100,000 acres of protected winter range in the Gros Ventre, not including the remaining winter range in Jackson Hole, including the 25,000-acre elk refuge.


Gros Ventre an alternative

“We’re fortunate that [the Gros Ventre] region of the ecosystem is still very much intact,” said Greater Yellowstone Coalition Wyoming representative Lloyd Dorsey, who authored the report. “By phasing out elk feeding in this region, we can capitalize on the natural bounty that exists, essentially for free, which ensures healthy wildlife and healthy habitat.”

“The climate is a Rocky Mountain climate, but let’s not forget these are Rocky Mountain elk,” Dorsey said. “All other states in this region, from Colorado through the Canadian Rockies, have bountiful herds of elk and other big game without feeding.”

Jackson Hole Conservation Alliance Executive Director Franz Camenzind called the “dire predictions” in the Roby report “grossly exaggerated,” although conservation groups do acknowledge that some reduction in elk numbers is likely inevitable.

Camenzind pointed out that the conservation groups favor a gradual phase-out of feeding and habitat improvement, including efforts to increase forage on the National Elk Refuge with irrigation. Refuge officials have already started improvements to the irrigation system. Camenzind said emergency feeding is also an option.

“In the worst winters, there would be some potential for feeding,” he said. “I would rather see a controlled reduction [in elk numbers] as opposed to a drastic one occurring through disease.”

The conservation groups are not asking for an injunction against feeding.

“We recognize that what the refuge is doing is an important part of this,” Camenzind said.

Roby said his earlier work on the consequences of ending supplemental feed still holds true today.  “If they do eliminate feeding up there, you can anticipate some kind of major losses,” he said.