Grand Teton National Park have developed an appetite for moose during the wintertime, a study shows.
Some 43 moose, including 25 cows, were found wolf-killed by Grand Teton and U.S. Fish and Wildlife Service researchers during the winters of 2010 and 2011. Preliminary data shows another 13 were killed during 2012, Grand Teton biologist Steve Cain said.
An exchange of emails between Park Service and Wyoming Game and Fish Department officials shows the study findings surprised biologists.
“Wow, I don’t think anyone can argue that wolf depredation on moose is not additive and that they are not having an effect on moose numbers,” Game and Fish large carnivore biologist Bob Trebelcock wrote in a May email.
Grand Teton biologist Sarah Dewey responded: “I agree that the number of moose kills is interesting. I think it reflects what is available to these packs and what in at least one heavy snow year was vulnerable. In 2011, emergency feeding was done in Buffalo Valley, which pulled a lot of the wintering elk up there.”
The two packs studied were the Phantom Springs and Pacific Creek packs, which each numbered 13 animals in year-end 2011 counts.
The packs were chosen because their home ranges are free of elk feedgrounds.
In addition to the 43 moose killed during the first two winters of the study, the packs killed 58 elk and four deer.
Predation dynamics in the summer differ significantly because of prey availability and risk, Dewey said in an interview.
“We’re close to the population objective for elk and have a lot fewer moose,” she said, referencing the 11,900 elk last tallied in the Jackson herd. “Elk are easier for them to go after. They’re both still risky for them to attempt to kill, but being a little bit smaller animal, there’s a little bit less risk with the elk.”
The two packs subsisted almost entirely on the smaller species during the summer, eating a diet of 93 percent elk.