If you’re cold, they’re cold. Bring them inside.

Amid snowfall and frigid temperatures with a wind chill knocking mercury levels down to subzero, that's one of the phrases that encourages people to bring their pets inside.

But what about animals that don't have four walls and a roof to escape the cold?

Wildlife

Don't worry too much about the forest critters out there, wild animals have a plethora of mechanisms and behaviors to help them survive the cold.

While some animals migrate out of the region completely, animals that stay start to prepare for the winter early, said Dr. Cody Thompson, mammal collections manager and associate research scientist at the University of Michigan’s Museum of Zoology.

To stay warm, lots of animals – even pets – begin to grow thicker fur with the changing of the seasons in the fall. They try to get fat and stay fat as the winter months approach, by eating and food-caching in the fall, slowing their metabolism, lessening physical activity, and sometimes still foraging through the winter.

Deer even portray an additional behavior to help keep the heat in by congregating in areas with trees with dense forest canopies to block the wind and snowfall, said Dr. John Bruggink, a Northern Michigan University professor of wildlife biology,

So, even though it's been miserably cold the past week, most animals out in the wild have been preparing for months and have more than enough resources and survival instinct to carry them through freezing temperatures.

“A week and a half ago, it was easier to forage for food, where now, their entire food resource is covered by six inches of snow. … And not only that but also having to search for those resources in these really cold temperatures," said Thompson. "It’s definitely a shock for wildlife but they’re generally really good at overcoming and making it through.”

The issue, Bruggink and Thompson said, is when Michigan winters go on for a prolonged amount of time and cold weather and snow stretches into spring.

"Say they go into winter with about a 90-day supply of fat, it'll start to thin out going into March, so in years where winter hangs on – especially if it's like a double whammy with cold temperatures and a lot of snow on the ground – that’s when it really starts to hit them hard," said Bruggink. "But they don’t typically freeze to death, they become more susceptible to starvation or being killed by predators because they’re in a more debilitated condition.”

Birds

While many birds hibernate to a warmer place, those that stick around also survive the cold by gaining as much fat as possible.

Dr. Ben Winger, an assistant professor at the University of Michigan and bird curator at the Museum of Zoology, used the example of American robins that avoid migrating as long as they can by finding berries to eat.

“Right now, in Michigan, you’ll see robins swarming any kind of ornamental tree that has berries on it because they know they just have to be constantly eating to survive," said Winger. "There are some populations that might have more mortality in a really cold year, but for others, so long as there's food, they'll be okay."

Once the robins clear out the berries, the birds are then forced to migrate in search of more food.To help the birds survive the cold, Winger said, people can provide seeds in bird feeders or thistle feeders."

Backyard bird feeders are good. I think for a lot of our resident birds like chickadees, titmice, nuthatches and woodpeckers – these are our species that don't migrate – they do well with sunflower seeds in the winter," said Winger.

However, for most other wildlife, experts recommend not to feed them. Not only could it make them sick, since the microbiomes in their gut change seasonally to suit the food they can find in the winter, but it can teach them to rely on humans instead of their foraging skills.

Additionally, if you see a wild animal in need of help, contact a licensed wildlife rehabilitation center from the Michigan Department of Natural Resource's list to make an expert decision.

Farm Animals

While a little less wild, farm animals come with their own winter to-do lists.

Many farm animals grow a natural winter coat to help endure frigid temperatures, but their domestication brings a certain level of responsibility to the people who own them.

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