The summer birds have all departed for southern climes or lower altitudes. Many of our human friends have done likewise. Those of us who remain are simmering soup, digging out winter clothes and making sure our homes are snug and warm. The birds who hang around all winter have the same needs—high energy food, winter clothes and snug, warm homes.

We can’t help much with the wardrobe—birds already have down jackets! When they get cold, they simply puff up their feathers, trapping warm air against their bodies. This works remarkably well—until the wind kicks in. And we have a lot of wind.

Before suburbia and urban sprawl, dead trees hung around for a while before falling. Woodpeckers drilled nest cavities in them. When the woodpeckers moved out, dozens of other species moved in. Chickadees, nuthatches, and many species of owls are just some of the birds who nest in tree cavities. Even more species use them as shelter on cold nights and during harsh winter storms.

The problem is that dead trees aren’t attractive, and they have a disturbing tendency to fall over, crushing houses and cars. Now, when a tree dies, we remove it. The result is a serious dearth of old trees full of holes. Since we caused this shortage, it seems only fair that we do something about it. There are several ways we can help.

If you’ve put up any nest boxes, those can do double-duty as roosting boxes. The important job for us is to make sure we’ve cleaned them out. All that used nest material can harbor a nasty array of blood-sucking parasites—mites and the like—and who wants a home full of pests?

You can also make or purchase dedicated roosting boxes. The difference is that these have the opening at the bottom instead of the top. Warm air rises, so the birds snuggled at the top of the box are toasty and out of the way of any cold drafts. There may also be perches inside a roosting box. Just avoid any box with a perch on the outside. While it appears to be a good idea, in reality you’re just putting out a welcome mat to predators and invasive species (such as House Sparrows).

I’ve even seen a roosting/nest box. It has two holes, one near the top and one near the bottom, and a piece of wood that can be pivoted so that only one at a time is open. Very clever.

Not all birds want to be enclosed in boxes. I’ve noticed rows of House Finches lined up under the eaves of our roof, all snuggled together with feathers fully fluffed. Other birds, such as the assorted flavors of juncos, seem to prefer the dense branches of evergreens. When we landscaped our lot, we included three pine trees and a half-dozen dwarf spruces and firs, along with a few mostly-evergreen broadleafed shrubs such as manzanita, cotoneaster, and Oregon grape holly (Mahonia). Not only do they offer wildlife shelter from the snow and wind, but they keep our winter yard from looking too dead and bare.

Even with a place to huddle, birds in cold weather burn a lot of calories. At the same time, most of the high-fat insects and grubs are either dead or hibernating out of reach. Birds that eat bugs during the summer are left with seeds and berries during the winter. While wild birds normally have no problem finding food—we feed them for our own pleasure, not to make a huge difference in their diets—winter storms are a different matter.

Normally, birds only get about 10% of their diet from any one source, including our feeders. They’re smart enough to realize that food resources come and go, and they shouldn’t depend overly much on any one source. However, during storms, seeds and berries may be buried under a thick layer of snow. Cold, wind, and blinding snow may keep the birds holed up, unable to search for food. If you feed the birds at all, don’t stop just when a storm arrives. You could literally be making a life and death difference. What should you feed? High-fat black oil sunflower seeds are one good option. So is suet. On a cold winter day, you’ll be rewarded by a huge crowd at your feeders.

I’m always amazed at the number of birds that seem to thrive in our Colorado winters, even when temperatures dip well below zero. It’s nice to know that I can offer them a warm welcome.