By Heather Brown

MINNEAPOLIS (WCCO) — Not all Minnesota birds head for warmer temperatures in the winter.

Birds like woodpeckers, sparrow, crows, hawks and some robins end up sticking it out up north.

That has Kathy from Roseville and Darlene from Forest Lake wanting to know: How do birds survive Minnesota winters?

“They’re built differently and they’re adapted to what they need to do,” says Jennifer Menken, assistant curator at the Bell Museum of Natural History.

When it’s cold or windy, birds find a place to roost. They’ll hide in holes in trees, under eves of homes, next to a tree or a thicket of pine.

Their feathers also provide a built-in down coat. Often they’ll fluff up the feathers and trap the warm air between the feathers and the body.

Most birds have a high metabolism and higher regular body temperature of closer to 104 or 105 degrees.

“Once you keep all that air in, it allows them to keep much warmer over the winter,” Menken said. “Now when it gets really cold, they have a hard time, too.”

A bird’s circulation system in their legs is also different from a human’s. It’s called counter circulation, and it means the veins in the bird’s encourage heat exchange between warm blood being pumped towards the feet and cool blood being pumped out. That’s why a bird’s legs don’t freeze.

Ultimately, what separates the birds that leave — warblers, orioles, herons and ducks to name a few — and birds that stay is food.

Insect-eating birds or birds that require open water fly south for warmer temperatures. Other birds who can eat seeds or garden waste or dried fruit often stay.

Menken says bird feeders don’t encourage any birds to stay that normally wouldn’t. They just make it easier for the ones that stick around in the winter.

Heather Brown