JACKSON — Managers of the National Elk Refuge in northwest Wyoming are seeing mixed results halfway into a 15-year management plan that set objectives for elk and bison populations, habitat conditions and other refuge issues.
Counter to goals, the average number of elk on human-supplied feed has risen significantly compared with the seven years leading into the 2007 Bison and Elk Management Plan. The intensity of feeding, which has occurred every year since the plan's completion, has stayed about the same, again counter to goals.
But in accordance with the long-term management plan, bison numbers are falling and the amount of natural forage on the refuge has jumped considerably.
Since the U.S. Fish and Wildlife Service approved the plan nearly eight years ago, one success story has been the irrigation system and its benefits for grasses and other elk food.
"We've increased average forage production by 16 percent," refuge biologist Eric Cole said.
"I can say with confidence that it has enabled us to start (feeding) later under some circumstances," Cole said. "Unfortunately, the net effect has been no change in the average feed season length."
Year-to-year variables — such as snow conditions, elk and bison numbers and the duration the animals are on the refuge — are among the reasons why the feeding season has not been shortened, he said.
In addition, the number of elk using the supplied feed on the 24,700-acre refuge has risen.
"In the seven years prior to implementation of the plan, the average numbers of elk on feed were approximately 5,800," Cole said. "In the seven years post, the average number of elk on feed has actually increased to around 7,000. So, clearly, we're not meeting that 5,000 elk objective."
Last winter, nearly 8,300 elk were tallied using the refuge's feed lines, the highest number since 1998.
However, efforts to reduce bison numbers have gone well thanks, in part, to hunting, refuge officials said.
"There were 1,250 bison the year we started" on the plan, refuge Manager Steve Kallin said. "If they had been left unchecked, I don't know what the population would be now, but it would be huge."
Based on hunter harvest and typical calf production, about 700 bison are estimated on the refuge. The goal is a population of around 500.
As for other refuge issues, Kallin said he believes there has been improvement since 2007 in habitat and disease management.
"One of the things that we have done is really stepped up our efforts for monitoring diseases and chronic wasting disease especially," Kallin said. "We've really stepped up the monitoring to ensure that if or when it would occur we would be on it right away."
Given the complexity of wildlife management in Jackson Hole, Kallin said he expected a gradual achievement of the many goals included in the 15-year plan.
"We've got 100 years of managing a certain way, and as we move toward modifying that, change will be difficult and it will be fairly slow, he said. "I can't say I'm surprised."