Despite winter exodus, elk pour through Wyoming migration bottleneck
JACKSON, Wyo. — The elk had returned, their passage spelled out in the drying mud along a Red Hills game trail that wildlife biologist Aly Courtemanch followed uphill.
Hoof prints showed up sporadically along the path, which fed into a bottleneck point along the “Path of the Pronghorn,” a protected wildlife migration corridor used by many species, including Courtemanch.
“There’s definitely been an elk through here since the storm last night,” she said.
It was late morning May 31, and minutes later the Wyoming Game and Fish Department scientist retrieved memory cards from a couple of remote cameras that affirmed her hunch. At 5:14 a.m. the same morning, a wolf had passed through. Two hours later, heading the opposite way, was a lone cow elk.
Images captured almost every day showed something moving, be it a band of elk, coyote, pronghorn or bighorn sheep.
“It sure is a thoroughfare,” Game and Fish’s Mark Gocke said.
Monitoring elk traveling along the migration route is part of a new Wyoming effort to determine if wapiti are returning to the Gros Ventre River country in summer and fall.
Last winter, for the first time on record, the herd almost entirely emptied out of the vast valley that reaches to the east of Jackson Hole. Historically there were scores of elk – nearly 4,500 of them just 14 years ago – but the winter population has been in free fall for the last five years. Last year it bottomed out at 86.
“It’s good to see that, yes, the elk are coming back,” Courtemanch told the Jackson Hole News & Guide. But questions remain: “What are those numbers? Is it a few hundred elk? Is it thousands of elk?”
Days later, after reviewing the camera data, she answered her own questions. It’s tough to count a critter that spends its summers in mountain meadows and high-elevation forests. But Courtemanch has a preliminary basement number – 1,964 elk – based on the animals that passed through the monitoring point. That’s about 18 percent of the nearly 11,000 animals in the Jackson Elk Herd, which includes the Gros Ventre elk.
“This is definitely a minimum count, as there were several large groups that went through and ‘mobbed’ the camera, blocking the view,” Courtemanch said.
“Undoubtedly, there are also groups of elk that migrated around the cameras on different routes that were missed,” she said, “and also groups of elk that migrated into the Gros Ventre from other winter ranges such as Dubois, Upper Green and Bondurant that wouldn’t have passed these cameras.”
A series of aerial counts throughout April and May turned up another 700 elk during the liveliest of the flights, though the remote cameras may have also picked up many of those animals.
Many elk that abandoned their traditional winter range last year have clearly returned. What’s less clear is how the Gros Ventre’s summer population stacks up to the herds of yesteryear. Hunter harvest data suggests a long-term decline, as do anecdotal accounts from the likes of Gros Ventre Wilderness Outfitters owner Brian Taylor.
“The numbers are down from what they were even 10 years ago,” Taylor said, “and the hunter numbers are starting to drop.”
Hunters downed nearly 1,700 animals during the Gros Ventre’s elk hunting heyday in the mid-1990s, more than half of which were cows, according to Game and Fish data. Since 2010, however, the kill count has hovered near 300 animals, and cow hunting has been almost entirely eliminated.
Although there’s a long-term drop in harvest, the short-term numbers are stable. The short-term trend suggests that the dramatic decline in winter numbers is being caused by a large-scale exodus, rather than a population crash, Courtemanch said.
A debate has brewed over what’s causing the winter elk distribution shift, and whether it’s significant. Wolves are a likely culprit, given that Game and Fish data suggests the Gros Ventre was recently the most wolf-dense landscape in Wyoming outside of Yellowstone National Park. But left without a major prey base last winter, the local wolf packs mostly took off for more fruitful hunting grounds.
In Taylor’s view, the cause of the change is clear.
“The wolf saturation is the No. 1 problem, absolutely no doubt about it,” he said. “And they’re starting to address that.”
The lifelong Gros Ventre rancher lobbied the Game and Fish Commission to target more wolves in his backyard last year, and the request was granted.
The agency proposed combining two Gros Ventre hunt units with a newly created area in the Upper Green River drainage and instating a collective hunting quota of 15 wolves. A year ago the cap on wolves that could be legally hunted in the Gros Ventre was nine animals.
Only time will tell, Courtemanch said, if the increased pressure and realigned hunt boundaries will attract elk back to the Gros Ventre.
“How much do you need to bring wolves down to see elk respond?” she said. “That’s a question we don’t know the answer to.”
Some conservationists say the experiment is fundamentally flawed, arguing that the Gros Ventre’s changes reflect a natural prey-predator interaction that shouldn’t be artificially manipulated.
“Predators moving prey across landscapes are indications of healthy ecosystems, rather than otherwise,” Sierra Club staffer Lloyd Dorsey said in May.
But wildlife managers view the winter absence as a bad thing.
Courtemanch pondered its significance on the bumpy drive out of the Gros Ventre after collecting her data. She called the abrupt winter shift out of the valley “striking,” biologically speaking.
“It’s a good thing that elk continue to come back in the summer and fall,” she said, “but it is a concern if the elk exodus continues in the winter.
“It’s not good from a disease perspective and a (National Elk Refuge) feeding perspective,” the biologist said. “We want them to stay up the Gros Ventre in the winter, too.”