Brrrrr. I woke up this morning to -17 degrees (that’s Fahrenheit!), and the weather folks are predicting cold and more cold. While I ventured out to refill the bird feeders, and I need to dig out the car later (something about mailing Christmas gifts), for the most part I can snuggle up at home, with the thermostat in the 60s and a cup of warm tea defrosting me from the inside out.
The birds aren’t so lucky.
As I watched my feeders through the window, I wondered—how in the world do these little balls of fluff stay alive, much less warm, when the temperatures are this low? Most sensible birds migrate (although that option also has its dangers), but most of my yard birds* are here year round. How do they survive?
With their high metabolisms, clearly these birds need to eat, and eat a lot! I’ve been carrying gallons of black oil sunflower seeds to the feeders and providing daily refills to my suet cages. Good thing this cold weather doesn’t last all winter, or my bird budget would be through the roof!
In very cold weather, suet is particularly important as a high energy food. I’ve noticed birds that normally prefer seed (such as juncos and finches) crowded around a suet feeder. I’m glad I have two suet stations separated by the width of our driveway. The nuthatches have monopolized one feeder, and they hang there all day. The block is frozen so solidly that it takes a lot of pecking to make a meal.
Most of the seed stays on the platform feeder, but enough falls off to attract a flock of ground feeding juncos. Imagine wanting to walk around barefoot in the snow! My feeders and poles are metal (the squirrels ate the wooden ones), and I cringe to see little bird feet holding on to the frozen steel. How do birds manage to avoid frostbitten toes?
Turns out that bird legs and feet are pretty frost-proof. They operate on a system of levers—tendons—and the muscles (along with their good blood supply) are all tucked up under the feathers where they are well-insulated. Of course, wet feet can still freeze onto the metal posts, but there is very little heat lost through a bird’s legs and feet. (That also explains how ducks and shorebirds manage to stand around in cold water all the time.)
Thankfully, the wind we had earlier has died down and things are relatively calm (for Colorado). The birds are daring to emerge from the shelter of the bushes and trees. With our Ponderosa pines and scrub oak (which still has dead leaves attached to the twigs and branches), and a number of nest boxes, , there are plenty of places in our yard for birds to huddle for warmth.
I know that Pygmy Nuthatches will crowd into an empty nest box or roosting box to share body heat, but I was surprised to see this same behavior on an exposed tree trunk. The entire time I was outside taking pictures (granted, not very long!), these three nestled birds never moved.
In addition to providing food and shelter, offering liquid water is another way we can help birds survive severe cold. My electric bird bath is managing to keep its contents from freezing, and it has a steady stream of customers. The evaporating water vapor has rimmed the pan with hoar frost, which I knock off when I notice it.
One fortuitous aspect of this cold snap is its timing. Christmas is approaching and many people have decorated their homes with lights—and lights (at least the traditional kind) produce heat. I’ve noticed birds snuggled up against the warm light bulbs, taking advantage of every source of warmth!
It doesn’t get this cold every year, but it happens often enough that the birds know how to manage. Those who survive will pass their hardy genes to their offspring, as they have for thousands of generations. Mother Nature isn’t always kind to the individual, but the species will endure.
* My typical winter yard birds include Scrub Jay, Steller’s Jay, Blue Jay, Black-billed Magpie, American Crow, Eurasian Collared Dove, White-breasted Nuthatch, Pygmy Nuthatch, Mountain Chickadee, Pine Siskin, Dark-eyed Junco, House Finch, European Starling, and a Red-tailed Hawk soaring overhead.