JACKSON, Wyo. — For a little over three decades, the local moose population has been experiencing a steady decline due to an amalgamation of natural and human-caused factors. Despite concern over the continuation of bull quotas in light of this, the Wyoming Game and Fish Department (WGFD) confirms Jackson Hole’s hunting season is not driving the chronic drop in numbers.
Although moose are one of the most visible charismatic megafauna in the valley, WGFD Wildlife Biologist Aly Courtemanch tells Buckrail that moose were not historically present in Jackson Hole. According to Courtemanch, moose naturally expanded into the area from Montana in the early 1900s with their population peaking locally in the 1980s. In 1988, WGFD’s data shows local moose numbers reached close to 1,200.
WGFD Public Information Specialist Mark Gocke says this is to be expected when moose populations pioneer into new habitats, most recently seen with a moose population in North Park, Colorado. Because moose are a browser species, they didn’t present competition to local elk, who are grazers; however, their population peak did lead to a reduction of willow communities, a primary winter food source (which have since recovered).
But Courtemanch suggests exceeding the carrying capacity of the landscape could be one of multiple, simultaneously occurring factors contributing to the long-term decline since then.
“I think it was partially exceeding the carrying capacity, predators, roads, disease and climate,” Courtemanch says. “It’s a lot of things that just started impacting moose at the same time, and unfortunately there’s not much we can really do about a lot of [those factors].”
Courtemanch specifically points to the reintroduction of wolves, the expansion of grizzly bears, increased prevalence of carotid artery worm and winter ticks due to warming temperatures, the 1988 wildfires that reduced habitat and chronic stress in response to increased activity from roads, people and dogs.
Courtemanch says the current moose population is down 70 percent from what it was in the 1980s. While the decline has flattened out in recent years, the population is still stuck in lower numbers. As of 2022, the Jackson moose herd winter trend count put the moose number at 297 out of the population objective of 800.
Gocke says this decline has sent many people his way questioning why moose hunting licenses are still being issued. Gocke emphasizes that the number of 2023 bull tags is substantially reduced from what it used to be, to a quota that might actually alleviate some stress put on females by the bulls during breeding season.
According to Gocke, too many bulls harassing females for an extended period of time, roughly two months out of the year, can actually add to the chronic stress the cows already experience from nutritional deficiencies, urban disruption, disease and predators, among other things.
“People immediately think hunting is the driver of a population, but hunting is not the driver here,” Gocke says.
According to Courtemanch, the current ratio of bulls to cows in the local population is 97 bulls per 100 cows, almost one to one, which is similar to what an un-hunted population would look like and many more than the population needs for reproduction.
Calf numbers have actually been increasing in recent years, Courtemanch says, although that increase has not yet resulted in higher population numbers overall. A new collared calf study starting this year is aimed at understanding why the moose population isn’t growing based on that calf trend. Despite that, Courtemanch suggests more calves is still a promising sign that the herd could start growing in the near future.
Visitors and community members can most effectively help support the current moose population by giving wildlife a brake, keeping dogs on a leash, giving moose at least 25 yards of space and never feeding moose or giving them access to foods in yards.
