A mule deer buck in snow.

CPW presents county with deer population outlook

Updated mule deer herd management plan available in the coming weeks

October 14, 2022

Colorado Parks and Wildlife (CPW) has presented updates to its upcoming mule deer herd management plan to the Board of County Commissioners. Mass recreation, persistent drought, chronic wasting disease, competition for habitat, and natural predation were noted as factors affecting local herd numbers.

As part of the updated plan, population objectives are being widened with the same midpoint to help the agency meet its goals and provide more flexibility in management. Sex ratios are also being decreased in some areas to help combat chronic wasting disease, which affects a greater number of bucks than does.

Julie Mao, CPW wildlife biologist in Glenwood Springs, told the board that herd management plans for data analysis units (DAUs) 13 (Roaring Fork Valley), 43 (east side of the Flat Tops Wilderness), 12 (North Grand Mesa), 41 (Garfield County west of Rifle and some of Mesa County) are in the process of being updated. She added that many aspects of recreation are unregulated, and therefore may affect deer herds in the area.

“In certain areas of the Maroon Bells, permits are going to be required for backcountry use,” Mao said. “That has been driven by pressure between recreationists. When it gets to that point where it’s too crowded for people, it’s way too crowded for wildlife.”

Off-leash dogs, and the loss of both habitat quality and quantity are additional problems local deer herds face, she added.

CPW’s updated population objective in DAU 13 is 7,000 to 9,000 animals, of which the unit has recently been in the lower part of the range.

“It’s slowly creeping up, but we’re hopeful that with regulating recreation and getting people to adhere to seasonal closures maybe that population can creep up to that 7,000 level,” Mao said.

She noted that chronic wasting disease (CWD) is a major concern in DAU 43, and not prevalent in DAU 13. Testing of animals in DAU 43 became mandatory in 2020, and the prevalence rate was 14 percent; CPW’s goal is at or less than five percent, and animals that contract CWD typically die within two years, she added.

“It’s going to persist in our environment, but as demonstrated in other herds, if we can target the age and sex class that is most likely to carry it, bucks and specifically older bucks, then we can control it through harvest management,” Mao said.

CPW Wildlife Biologist Genevieve Fuller noted that the population objective in DAU 12 is 17,000 to 23,000 deer, of which estimates are just below the goal (16,500). She added that CWD is a growing issue in DAU 41 (population objective of 6,500 to 8,500, and estimated at 4,500 animals), while it isn’t a problem in DAU 12.

“A lot of the herds north of I-70 are seeing an increase in chronic wasting disease prevalence,” Fuller said.

Loss of quality habitat from persistent drought and competition from elk and moose are factors affecting deer numbers in the region. New plant growth in the wake of the Pine Gulch Fire is providing a boon for deer in DAU 41, she added.

“Turkeys are utilizing it, too,” noted Commissioner John Martin, who also asked CPW staff to look into positive relationship between grazing cattle and deer in these units. “We like to keep track of the turkeys and mule deer around here.”

The plan, which is currently being written, is slated to be available later this month or in November, after which a 30-day public comment period takes place.

“There is overadvertising, overpromotion, overdevelopment of every place you have talked about,” said Martin. “Yes, it’s all nice, but we don’t have to go overboard as we have in reference to development and the promotion of getting everybody out there. Tone it down a little bit and the herds will be better off, and we won’t overuse it like up in the Maroon Bells. Overdevelopment and overpromotion is killing everything, so put down tourism as a form of predation for wildlife.”