Wildlife: Wintry weather to take toll on Colorado mule deer

Mule deer enjoying an abundance of January forage as a sustained warm spell has melted low-elevation snowpack in Colorado.
Last year, mild winter conditions eased foraging conditions for ungulates, but this year’s cold temps and deep snow could result in increase mortality. @bberwyn photo.

‘Wildlife has been experiencing and surviving severe weather for eons without human intervention’

Staff Report

Harsh winter conditions in northwestern Colorado may take a toll on already struggling mule deer herds, state biologists said last week, explaining that they’ve started a limited feeding program to try and keep ungulates from invading cattle grazing areas.

The recent storms have created conditions ranking among the most extreme in the past 35 years. Temperatures dropping well below zero and deep powder snow atop brittle crusts are making it harder for deer and elk to forage and could lead to increased wildlife mortality in portions of the region unless the weather moderates significantly, according to Colorado Parks and Wildlife.

The area experiencing the most severe impacts includes Moffat, Routt and Rio Blanco counties. Eagle, Garfield and Jackson counties have developed severe winter conditions more recently and managers in Grand and Summit counties are also expressing concern.

“I’ve just returned from a tour of the area and based on what I saw, we will likely see some significant impacts to wildlife,” CPW Regional Manager Ron Velarde said in a press release. “But people need to understand that, despite how damaging conditions are right now, wildlife has been experiencing and surviving severe weather for eons without human intervention, so it’s important to have the proper perspective.”

Colorado Parks and Wildlife’s Northwest Region is home to moose, mule deer, greater sage-grouse, elk, pronghorn and many other species that may be affected; however, the impact to the mule deer population is a specific concern. Over the last decade, the species has seen a continued drop in numbers in parts of Colorado and across the Western United States due to a variety of factors.

A wet summer and mild early winter conditions helped get many species into good shape leading up to the severe winter outbreak, and state efforts to boost mule deer populations have been paying off, with highsurvival rates of adult and fawn mule deer in northwestern Colorado in recent years. But biologists said this winter will cause those numbers to drop.

In the Meeker area, wildlife manager Bill de Vergie said the severe winter has led to numerous reports of conflicts, primarily elk and deer entering private land and causing damage to haystacks and utilizing cattle feed lines.

“All we can do is respond as best we can on a case-by-case basis while nature takes its course,” de Vergie said. “We can usually influence many of the threats to deer populations using a variety of management actions, but we have no control over weather.”

For now, the state agency is not prepared to start a large -scale feeding program to address potential starvation.

“By policy, certain conditions have to be met before an emergency feeding program can be considered and we are not there yet,” said Velarde. “But what is very important for the public to understand is that, although we may see short term effects from feeding, our experience has shown that it has had limited long-term benefits overall.”

Velarde adds that feeding operations in areas where chronic wasting disease has been detected, including many areas within the Northwest Region, can only be approved by the CPW Commission. It limits emergency winter feeding for mule deer to those areas where winter mortality of adult female deer is expected to exceed 30 percent.

According to Senior Terrestrial Biologist Brad Petch, the agency is monitoring adult doe and fawn survival with several hundred radio-collars. In addition, CPW personnel are conducting extensive visual observations of herds and inspections of carcasses to determine body condition and cause of death. Based on current observations, mortality is less than 10 percent.

“That percentage can certainly change quickly under such conditions,” said Petch. “Our personnel are keeping a very close watch on conditions and mortality, and we will continue to do so through the rest of the winter.”

Colorado Parks and Wildlife reminds the public that feeding wildlife at any time can be very detrimental to their long-term survival, in addition to being illegal. Some non-natural foods can lead to severe digestive ailments that can cause death in ungulates like mule deer and elk. Feeding concentrates wildlife, increasing the likelihood of disease transmission. In addition, it can lead to a dependency on human-provided foods, change natural migration patterns and attract predators.

“We understand that people want to help in situations like these,” said Velarde. “But feeding should only be done by professionals, if it’s done at all. If people take matters into their own hands, it will likely do more harm than good, leading to wildlife deaths, and can also result in citations and fines.”

Velarde adds that the most effective way for people to help wildlife stressed by winter conditions is to limit activities on winter ranges, where deer and elk are finding shelter and foraging for what food remains available. Human-caused disturbance leads wildlife to expend critical energy necessary for survival during the coldest time of the year, he said.

To learn more about mule deer and Colorado’s effort to address their decline, see Colorado’s West Slope Mule Deer Strategy.


One thought on “Wildlife: Wintry weather to take toll on Colorado mule deer

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s