The sudden intensity with which severe winter weather swept into Northwest Colorado in late November has created concern about how mule deer herds will come through the season.
"This is the first winter in quite a while that we've asked wildlife managers to closely monitor the condition of the animals," said Randy Hampton of the Colorado Division of Wildlife.
There are no overt signs that the deer have suffered from the difficult conditions that make it hard for them to reach food. But the winter is young, and the effects of poor forage and extreme cold may not show up until April, Hampton said.
Routt County has received 200 inches of snow at higher elevations this winter. And during the first week in December, overnight temperatures of 35 degrees below zero were recorded in some low-lying areas.
The DOW avoids supplemental feeding of wild animals, but deer and elk have been fed during the harshest winters. That's far less likely to happen in Northwest Colorado this winter because chronic wasting disease has been detected in a few deer and elk in this part of the state. It is thought that the disease, which attacks the animals' nervous system, is more rapidly spread when the animals are bunched up. Feeding the animals causes them to congregate more than they might have otherwise.
Supplemental feeding is against DOW policy in most game units in Routt, Moffat and Rio Blanco counties; however, Hampton said, it's possible that DOW officials would re-evaluate the policy as the winter weighs on and the condition of the deer herds are monitored.
Deer and elk historically have migrated out of Northwest Colorado's high country during the winter and sought refuge in warm microclimates such as the Bond area in South Routt. However, fence lines, highways and encroaching development have cut off some of the traditional migration routes. As of mid-December, wildlife managers in the Steamboat area had not reported seeing deer. But in recent winters, small pockets of mule deer stranded in Steamboat's deep snow have been observed.
Elk are hardier than mule deer. Hampton said his agency doesn't worry about the animals making it through the winter. Deer are less immune from the hardships of winter and, perhaps not coincidentally, are more determined in their annual migration.
Deer and elk have different digestive systems and nutritional needs. Elk can feed on grasses, and their diet could be supplemented with meadow hay. Mule deer are known to feed on more than 800 species of plants, but most of those are not available in winter, when they are reduced to a near starvation diet of twigs and depend more heavily on browsing the tips of shrubs. The Utah Department of Wildlife reports that mule deer subsist to a great degree on stored fat to get them through the winter, when they can lose as much as 20 percent of their weight.
Hampton said deer in Northwest Colorado went into the winter with good energy reserves, but the hard crust that developed on the accumulated snow in December will make it more difficult to get at more nutritious food than in milder winters.
Special feed pellets are the most practical way to supplement the diet of deer.
DOW employees are trained to make visual inspections of deer to gauge their condition. Generally, the amount of angularity observed on their bodies indicates they don't have sufficient nutrition. However, wildlife biologists can learn the most from the carcasses of dead animals, and deer that have become road kill often are analyzed to get a clearer picture of how the winter is affecting them, Hampton said.
No matter what the case, it is illegal for members of the public to feed wild animals in Colorado. That is especially critical because of the presence of chronic wasting disease in the area, Hampton said.
DOW officials say people could do more to help deer and elk make it through the winter by keeping pets leashed.
Deer and elk that must run from dogs also are forced to use the energy stores that they need to get them through the winter. Even if the animal is not caught, the stress of the chase is exhausting and could cause the animal to die later.
-- To reach Tom Ross, call 871-4205 or e-mail firstname.lastname@example.org