There is a tiny bird that lives in the Adirondacks whose body weight equals that of two pennies. Its overall size in not that much bigger than a hummingbird, and it does not migrate south to escape the freezing temperatures of the North Country. I often think of these birds as the late afternoon sun dips behind the mountains and the clear star-lit skies suck back up all the warm air that felt so good during the sunny day. I think of what it must take for this bird to survive just one night at 24 below zero Fahrenheit.
I’d like to introduce you to our resident member of the Regulus family, the golden-crowned kinglet (Regulus satrapa). I say resident member because its close relative, the ruby-crowned kinglet (Regulus calendula), has a better exit strategy by migrating south each fall. I guess some just can’t handle the rigors of winter life in the Adirondacks!
If you have ski, snowshoe, or hike through the Adirondack woodlands you may have come across this olive-drab colored bird with a boldly striped head and face. Atop these stripes sits an often concealed crest of golden feathers, shown mostly when agitated or courting. Kinglets can often be seen hovering just on the undersides of eastern hemlock or balsam fir branches feeding on hidden spiders, eggs, caterpillars, and other hibernating insects. The kinglets’ call notes of tsee-tsee can be heard throughout the day as it keeps in touch with the other members of the group that are feeding in the forest.
So last night after I washed up and brushed my teeth, I hopped into bed with my flannel sheets and down blanket. As I lay there toasty warm, and the winter winds rattled the windows I thought again of the little kinglets. How do they survive the night
The key to surviving an Adirondack winter (in the bird world) is to eat, eat, and eat some more. Kinglets, and other winter resident birds, want to keep a good layer of fat surrounding their insides because that is what keeps them fueled through a freezing 13 hour night of shivering. In the morning as the temps creep up to zero they can wake up fresh and ready to face another day of eating bugs. Oh by the way, they also need this fuel to maintain a constant body temperature at around 110 degrees F.(humans are 98.6 F)…hot little birds.
But kinglets have no bed to sleep, nor roof to cover them, or do they? After some exhaustive research, the Biologist/Author/Professor-Bernd Heinrich wrote in Winter World: The Ingenuity of Animal Survival, that kinglets may be spending the winter nights huddled together with several other kinglets (for body warmth), nestled under a pillow of thick snow on a tree branch. We see a similar strategy used by ruffed grouse as they burrow alone under loose snow and use the insulative quality of the white stuff. It was also revealed that some birds can go into a state of torper or lowering their ” internal thermostats” to conserve energy.
An amazing fact is that many birds can restrict blood flow to their legs and feet but allowing just enough blood to keep the tissue from freezing. Don’t we wish we had such abilities. Energy conservation is the name of the game with winter survival – and we thought we had all the answers to energy conservation!
Another insulation technique that birds often use is to fluff up their feathers to trap a layer of warm air in the soft downy feathers around their body. If you have ever held a bird in hand you probably noted how much space there is between feathers and actual body of the bird. Makes me think of how much I enjoy my down coat on these chilly days.
Earlier this week we experienced a bit of a “January thaw” with rain and strong winds. Again my thoughts go to birds in these conditions. We can think of feathers as a layered system of protection, not unlike the shingles of a layered roof. Rain falls onto the feathers but does not seep through to the skin because of these built-up layers. Also a bit of waterproofing is applied to the feathers from an oil gland near their rear-end.
So our kinglet may look bouncy and playful all day long in our Adirondack woods but it’s cuteness hides the dogged determination that they need to find the food, build the fat, and keep the internal fires burning.
Well what a marvel of self efficiency we see in birds. They carry the roof, furnace, insulation, plumbing, and electricity all in a bundle of well-adapted anatomy and physiology!
Photo: Golden and ruby-crowned kinglets plate from Natural History of the Birds of Eastern and Central North America, 1925. Original painting by Allan Brooks.