Wildlife managers, federal agencies, nonprofit partners and the public are continuing efforts to bolster the Sheep Mountain mule deer herd.
Through the Wyoming Game and Fish Department’s Sheep Mountain Mule Deer Initiative, management agencies and cooperating partners have been focusing on growing the herd size and improving the experience for hunters since about 2015.
The Sheep Mountain mule deer herd includes hunt areas 61 and 74-77 and occupies an area from the Colorado border in the south to Hanna in the north.
The initiative is a big-picture effort undertaken in conjunction with similar work on other herds around the state. Mule deer populations have been in decline for decades, prompting the creation of the statewide Wyoming Mule Deer Initiative about five years ago. The goal is to bolster and stabilize herd numbers by working with the public, private landowners, federal agencies and conservation groups.
Herd size stableDuring a meeting Thursday evening, Game and Fish biologist Lee Knox presented findings from a multi-year project in which 60 mule deer does wore GPS collars from 2017-19. Biologists collected data points every two hours for two years.
“We’re getting a better understanding of this herd,” he said. “We didn’t know a whole lot about migration routes.”
Knowing where the deer spend most of their time allows wildlife managers to pinpoint habitat work on high-frequency areas. They can also get a better understanding of survival rates, which will allow them to better calculate population estimates.
Knox said about 80 percent of the collared does survived each year, which is an expected number for a stable population. Causes of death included predation by mountain lions and coyotes, vehicle collision, fence entanglement, archery hunt and infection.
Biologists sampled 15 does for chronic wasting disease — the test to detect the disease can only be done on a dead animal — and nine were positive.
“Forty percent of the deer that had died were positive for CWD,” Knox said.
The herd objective is 10,000 members, and it currently sits at about 6,600, down from a high of about 7,000 in 2016. The fawn-to-doe ratio, one indicator of herd growth, suggests the herd is stable.
“It doesn’t seem to be growing, but I don’t think our population is in decline either,” Knox said.
Mitigating chronic wasting disease
Among the many potential stressors on a mule deer in southeast Wyoming, chronic wasting disease is one that has attracted a lot of attention recently.
Game and Fish is in the final stages of preparing a CWD management plan, which should be adopted this spring. The plan lays out a host of potential treatments for mitigating the prevalence of the disease and slowing its spread.
Knox said that as CWD increases prevalence in a herd, doe survival decreases, which suppresses overall herd size.
“At that rate, it’s very difficult to grow mule deer on top of all our other mule deer concerns,” he said.
A potential strategy for stabilizing a herd is to reduce the number of older bucks, which are the most likely to have the disease and thus transmit it to younger animals and does, upon which herd survival depends. Wildlife managers could change hunting regulations or season dates to reduce that age class.
Another strategy is to reduce “hot spots,” or places where deer congregate. CWD prions are spread from animal to animal, but they also survive in the environment where diseased animals are present.
In short — people shouldn’t feed deer.
Game warder Bill Brinegar said he sees a lot of homeowners in Centennial, Woods Landing and Jelm feeding mule deer.
“You think you’re helping the deer,” he said. “You’re not.”
Many of the deer congregating on private land are CWD positive, he said, and they’re spreading the disease to healthy deer.
“Be responsible,” he said. “Do your part.”
Habitat projects continue
The U.S. Forest Service is a major partner with Game and Fish when it comes to habitat work aimed at supporting big game populations. Laramie District Ranger Frank Romero said components of the Medicine Bow Landscape Vegetation Analysis project, or LaVA, will benefit mule deer. The plan calls for a variety of treatments on up to 360,000 acres over the next 15 years. A draft record of decision for the plan, which has been in the works for several years, is expected this spring.
“It’s about habitat,” Romero said. “That’s a big part of the project.”
Game and Fish habitat biologist Ryan Amundson agreed with Romero.
“I think we can really do some good,” he said of the Forest Service and the LaVA project. “We’re going to be very supportive of their efforts.”
A range of habitat projects are underway or have been completed, often with funding from partners such Muley Fanatic Foundation and Rocky Mountain Elk Foundation.
Amundson said collar data will be used to find and remove migration barriers, such as fences, and improve summer range, transition range and winter range.
The goal with any habitat project is to improve species diversity, vegetative production and nutritional value, especially in aspen stands and riparian areas.
“Does are seeking out that higher quality vegetation,” he said. “It’s about habitat effectiveness.”
Several projects now underway involve thinning conifers from aspen stands in preparation for prescribed burns, which will encourage aspen regeneration and understory growth.
“Aspen like it really hot,” Amundson said.
On the east side of Sheep Mountain near Lake Hattie, a plan is underway to replace woven wire fence used to contain domestic sheep with fencing that has a smooth bottom wire and a top wire low enough for jumping over. The parcel in question is a popular winter feeding spot for mule deer and pronghorn.
Other habitat projects include shrub mowing to encourage regeneration, replacing an irrigation diversion structure that waters about 20,000 acres near Arlington and monitoring and spraying burn areas to control cheat grass.