Critters on Ice

It’s not the cold that kills. Wild animals evolved to survive extreme winter weather. They have fur and feathers and other means that help them survive the worst conditions nature throws at them.

“It’s really the combination of deep snow and extreme cold that can kill turkeys,” says NWTF regional biologist Rick Horton. He lives in northern Minnesota, so he gets to see first-hand how wildlife copes with severe winter weather. “There has been some research that shows cold weather really isn’t that hard on turkeys. They can survive long periods of extreme cold. However, deep snow that stays on the ground for a long time can really make it hard on turkeys.”

It’s also tough on deer. Quality Deer Management Association outreach and education coordinator Kip Adams says healthy white-tailed deer in northern climates normally build fat reserves throughout the summer and fall that can sustain them for about 90 days. Once that fat is used up, survival becomes a battle.

“The longer deep snow stays on the ground, the harder it is for deer to survive,” explains Adams, who was the deer project leader for New Hampshire Game and Fish before joining QDMA. “If it starts snowing in November and it doesn’t melt until March or April, then you start to see die-offs.”   

To preserve that fat, northern deer will move as little as possible and stay in places that offer the most protection from the elements for months at a time. Often called deer yards, those spots normally consist of thick conifer trees, like spruce, cedar and pine, which catch and hold snow on their limbs. That makes it easier for deer to walk around and the snow-covered limbs can actually serve as a layer of insulation.

“They eat buds and twigs and some evergreens, like white cedar, when the ground is covered in snow, but those foods have little nutritional value,” explains Adams. “They need to eat something to keep their digestive systems working. That creates vital body heat.”

Turkeys can go several days without food, but they still need to eat regularly, as well. If they don’t, they burn up what little fat reserves they have and will even start to lose muscle mass.

“Turkeys that live in farm country tend to do better in the winter than those in areas that don’t have any agriculture,” says Horton. “They can find leftover grain in fields, undigested grain in cow manure and they will hang around farms and pick up various foods around silage bins and even in feed lots. It’s not unusual to see large flocks of turkeys hanging around barns and other areas with potential food where I live. I even see them along railroad tracks, where they pick up spilled grain from the rail cars.”

They can’t reach food buried under two or three feet of snow, and they have a difficult time walking through it if the snow is soft. That’s why northern turkeys often spend their day on packed snow around farm operations, herds of cows and even in rural roads and on railroad tracks. They also seek areas with overhead branches that catch snow. If they don’t have those options, they’ll simply stay up in trees and wait, nipping on buds to put something in their systems. Eventually, the snow will get enough ice crust on the surface that they can walk on it.

“Turkeys will move quite a way to find what they need,” says Horton. “Up here, they have different territories for different seasons.”

NATURE CAN BE CRUEL

Even with a number of natural survival adaptations, severe winters can take a toll on a variety of wildlife. An estimated one-third of deer in parts of Maine died a few years ago as a result of deep snow that stayed on the ground well into the early spring.

“The worst I saw in northern New Hampshire was when about a quarter of all the deer died from winter weather conditions,” says Adams. “It was the worst winter in decades. The snow was deep, and it stayed on the ground well into April.”

Fawns typically die first. Their shorter legs and smaller bodies have a difficult time moving through deep snow, so they burn up fat reserves faster. What’s more, they often don’t carry as much fat into the winter as adult deer.

“Fawns are also more prone to predation,” notes Adams. “Coyotes and other large predators can catch fawns easier, because they have more trouble moving through the snow than adult deer.”

Horton says turkey populations at the northern edge of their range will also rise and fall based on winter conditions. Hens that survived a harsh winter will often lay fewer eggs, resulting in a decrease in overall turkey numbers the following year.

WHAT CAN YOU DO?

No one likes to see deer, turkeys and other wild animals suffer. That’s why lots of people feed wildlife in the winter. Don’t do it. Many wildlife experts agree that’s the worst thing you can do. A sudden change in diet can have significant and even fatal results, particularly on deer.

Feeding can also spread disease, and it familiarizes wildlife to humans, which can turn them into nuisance animals. It’s expensive, too, and some people simply stop feeding after realizing how expensive and time-consuming it can be. That can also be fatal.

Instead, says Horton, work on improving the natural landscape. Create better winter habitat and plant things that provide food well into the winter. He’s a big fan of crabapples, highbush cranberries and other plants that hold fruit and seed all winter.

“Avoid disturbing wildlife in the late winter,” adds Adams. “The less they have to run or fly, the better their chances of survival. That uses up a lot of energy that they need to make it through winter.”

Sometimes though, deer, turkeys and other wildlife don’t survive a severe winter. But for every animal that dies, another lives. Crows, ravens, vultures, coyotes and a variety of other scavengers will feast on the carcasses of the dead. Nature can be cruel, but in the cycle of life, nothing goes to waste.  

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