Winter tests big game animals, but they’ve adapted to harsh conditions

After several mild winters in a row, this winter is starting to look a little more "old fashioned" with ample snow in the mountains and frosty temperatures in the valleys, but most big game animals around the state are doing fine so far. 

"Contrary to the warmer, wetter conditions predicted during an El Nino, this winter is about normal in terms of precipitation and temperatures for this time of year, which are conditions big game animals can survive," said Brad Compton, Fish and Game's assistant wildlife bureau chief. "But we have a lot of winter ahead of us, and Fish and Game will be closely monitoring the herds and seeing how winter conditions affect their survival."

The first survival mechanism for most big game animals is migrating to lower elevations where weather is milder and forage available. These areas are commonly known as "winter range" and you can see hundreds, if not thousands, of animals congregating there. 

Animals spend months on winter range feeding, or trying to feed, but forage is slim and usually doesn't provide enough nutrition to sustain animals. That's why one of the most important survival factors for big game animals is the body fat they carry into winter. Fish and Game personnel check the body conditions of animals taken by hunters in the fall. Those animals are representative of those remaining in the herds.

Animals with abundant body fat can survive most weather conditions, but even in the healthiest animals, fat reserves are limited and must be conserved. People can help animals from unnecessarily burning energy by avoiding areas where herds spend the winter, and if you encounter deer and elk, don't disturb them.

"Enjoy them from a distance, but if your actions cause them to move, you're too close," said Daryl Meints, Fish and Game's big game manager for the Magic Valley Region. 

While big game animals have endured Idaho's climate for eons, populations tend to be cyclical. Herds flourish after mild winters, and decline during harsh winters. 

As wildlife managers, Fish and Game strives to keep herds within the biological and social carrying capacities, but winter survival is a complex equation with many moving parts. Ensuring quality winter-range habitat is a primary way of maintaining healthy herds. Fish and Game, other state and federal land managers, and private landowners contribute to providing winter range to maintain healthy herds.

Supplemental winter feeding is another way Fish and Game can mitigate for extremely harsh conditions. But it's done carefully and typically limited to emergency situations when abnormal weather overwhelm a herd's natural ability to endure winter, or wildlife damages private property. 

There are winter feeding committees in each of Fish and Game's four regions that periodically conduct emergency feeding. These committees provide timely information to Fish and Game regional supervisors so supervisors can decide whether emergency conditions exist and winter feeding is needed.

Advisory committees and Fish and Game monitor snow depth, temperatures and quality of forage on the winter range. Extreme weather can also trigger winter feeding, such as five consecutive days when temperatures stay below zero degrees, and snow depths of more than 18 inches on south facing slopes. But other variables also affect the decision. For instance, an 18-inch snowfall combined with mild temperatures in December may not constitute feeding, while snow crusting - a condition when deep snow hardens and makes foraging difficult for animals - might trigger it. 

Regardless of the severity of winter, some animals naturally perish. That's an inescapable part of nature, and animals too stressed from winter can die even when they are fed. There's also a Darwinian irony about winter feeding stations: strong animals that would survive without supplemental feeding may drive off the weakest animals that will perish without it.

If current weather conditions continue with average to slightly above-average precipitation and normal temperatures, emergency feeding probably won't be necessary. However, Fish and Game is ready to implement it if necessary should winter conditions turn for the worse 

Here are reports from wildlife managers in each region: 

Panhandle Region
Northern Idaho experienced extremely low rainfall last summer. Big game animals may not have had as much nutritious forage as would be available under more normal conditions. Although no body condition data were collected, Panhandle big game likely entered the fall and winter with lower-than-average fat reserves.

Air temperatures were above average during October and November. Typical November snows blanketed the higher elevations, but fell as rain in the valleys. While significant rains occurred, the first snowfalls that covered valley floors and remained did not occur until mid-December. Heavy snowstorms followed with more than 2 feet of snow falling between Dec. 22 and 24.

Landowner problems with elk, deer and wild turkeys feeding on stored and fed hay have been significant. Depredations have been more numerous and more extensive than at any time in the last four winters. Those winters were exceptionally mild and natural forage was abundant and accessible.

Big game winter mortality is often caused by extended periods of continuous snow cover. Such conditions make food less available and more energy is required to access it. Because lower elevations did not get snow until late December, Fish and Game biologists are cautiously optimistic that the Panhandle's big game populations will not experience extraordinary winter mortality. Long-term weather patterns suggest that Panhandle temperatures will be slightly above average through the remainder of January and February.

Clearwater Region
Despite snow at lower elevations than it's been in several years, the Clearwater Region is slightly below normal for snowpack and has also escaped most of the frigid weather that hit other parts of the state in late December.

Big game managers say it's a normal year and there's no concern at this time for excessive winter mortality for big-game animals. Winter feeding very rarely occurs in the region, so it's highly unlikely that it will happen this year. Most animals came into the winter in good condition, so there should be good carryover into spring and beyond. 

Southwest Region
Deer and elk were in fair-to-good shape entering winter, but some fawns captured during radio collaring in early January were slightly lighter than usual, and body weight is an indicator of how well they survive winter. There was record fawn survival in recent years with up to 90 percent living into spring and beyond, but biologists estimate this winter could drop that down to around 60 percent fawn survival, which is the long-term average. 

Snowstorms during late fall drove animals off summer range a little sooner than in recent years, which meant they had less time to add body fat before arriving on their winter range. 

Most areas of the region are experiencing normal snowfall and temperatures, although snow depths are deeper than in recent years. A cold snap in mid-and-late December has ended and temperatures have warmed, but there are about two months of winter weather remaining.

Biologists are monitoring elk wintering along the Salmon River where the Teepee Springs fire burned last summer, and they may initiate emergency winter feeding there if needed due to loss of forage. 

The Soda Fire in the Owyhee Desert also burned vast acreages and may have meant mule deer had less forage to gain weight during summer. 

Deer and elk are wintering at lower elevations than in recent years and can be seen near Interstate 84 between Boise and Mountain Home. 

Aside from areas affected by the Teepee Fire, it's unlikely emergency feeding will be necessary in the Southwest Region this winter. However, a prolonged winter can claim animals even if snow isn't unusually deep or temperatures unusually cold because animals run out of fat reserves and can't survive until spring green up. 

Magic Valley Region
Snowfall in the region was above-average for December, but most snow levels are currently at average or slightly above average. A December cold snap also broke and the region is seeing warmer temperatures so far in January. Like elsewhere, there are a couple of months of winter weather remaining, and a wet, cold spring could also pose a threat to animals. 

The area recorded its highest survival in the last two years, peaking around 80 percent, but biologists expect it to drop this winter to average. Since 1998, fawn survival in the region has averaged about 65 percent and ranged from 80 percent survival down to 20 percent. There is no emergency feeding in the region so far, but there is a special feed site near Sun Valley where about 200 elk winter. It's intended to keep the animals out of Ketchum and away from Idaho 75.

Southeast Region
Deer and elk checked during fall hunts showed animals in very good conditions coming into winter. The area has received less snowfall than other parts of the state, but still about average for the region. Fish and Game is receiving reports of elk feeding on haystacks in the Soda Springs and Montpelier areas. People should also beware of animals crossing highways in those areas. 

Winter feeding committees are monitoring conditions, but no feeding has started. The last time emergency feeding occurred in the region was in the winter of 2012-13 near Pocatello. 

Deer herds are the primary concern for big game managers, and they are hopeful for an average winter with normal deer survival to maintain healthy herds in the region. 

Upper Snake Region
Animals were in good-to-excellent condition entering winter. Moderate rain during fall resulted in good fall forage for big game. Mid-December saw normal to below-normal temperatures and above-normal precipitation. With the moderate amount of snowfall coupled with colder temperatures in mid-December, big game animals, primarily elk and deer have been observed in large herds on winter ranges. There were areas in the region with severe cold and above-normal snowfall, which will make forage for animals more difficult than in the previous mild winters.

Fish and Game officials report haystack depredations throughout the region in late December. Depredations are moderate to high throughout the region. Most deer and elk are finding forage on winter ranges, but the surplus of stored hay throughout the region is attracting more animals than usual. Elk remain the highest concern for future depredations with deer, antelope, and moose remaining at a moderate level under current conditions. 

No winter feeding has started in the region, but Fish and Game officials will continue monitoring herds throughout winter. 

Salmon Region
After wintering at elevations up to 9,000 feet the past two winters, deer and elk have mostly returned to the valley floors in the Salmon Region.

Most of them are in good shape because the region had good-to-excellent forage after favorable wet weather hit the region during key times during 2015 and provided good plant growth. 

However, that's not across the board, and the region sees higher fawn mortality in a normal year than most other areas of the state. 

The bad news is elk herds that have had the option of wintering at higher elevations in recent years have returned to valleys and found haystacks to feed on, which causes problems. 

The area received a lot of snow coupled with cold temperatures in December and the snowpack was about 120 percent of normal heading into January. Cold weather has persisted in the area, and without warmer temperatures the area could be heading into a severe situation for wildlife. 

Fish and Game managers say that could be tough on the region's deer herds and they expect some mortality, but most elk should survive. 

How many deer survive will largely depend on what happens with weather for the rest of the winter. Fish and Game crews in the region wrapped up their deer trapping in mid-December, and all of the radio collared fawns were still alive in mid-January. The area doesn't have a history of winter feeding, and there are no established feed sites. ​