Laura Erickson's For the Birds

Black-capped Chickadee

(Recording of a Black-capped Chickadee)

Winter in the frigid Northland can seem like an endless ordeal to a displaced southerner, but to offset the season’s bitterness, to brighten even the worst blizzard, we have the chickadee.

(Recording of a Black-capped Chickadee)

The Black-capped Chickadee is little more than fluff and fire. It weighs only a third of an ounce–you could mail three of them with a single postage stamp. But, encased in its warm down coat and cap, the chickadee is perfectly adapted to the worst Northland winter. Its body is shaped about as spherically as a bird can get, to reduce its surface area and conserve heat. Its tail feathers are long, but feathers are like human hair–they don’t have any circulation and so don’t lose heat. The feet and legs on all perching birds contain no fleshy muscles at all–only tough tendons with a limited vascular supply. The temperature of the feet can drop to near freezing, and the blood flow can be shut off just about completely, when the air temperature is low. If a chickadee loses a toe on a cold day, it probably won’t bleed–it may not even feel it. The feet of perching birds have a very small nerve supply–so few nerves that Gray Jays have perched without apparent discomfort for almost a full minute on a hot camp stove.

Chickadees join winter feeding flocks in fall, and move around together through a winter territory. It’s easy to attract them to your window. They’re fond of sunflower seeds, suet, cracked walnuts, peanut butter, and cracked corn. Their eating method seems very inefficient– they snatch a single seed or bite of suet and fly off to eat it in a tree or shrub. They peck a small hole in a sunflower seed and take tiny bites of the heart within, and then return to the feeder just to grab another seed and fly off again. It seems like the work involved must exceed the amount of energy they get from the meal, but, then again, it’s hard to imagine how anything as busy as a chickadee could get its energy no matter how it ate. When sound asleep, a chickadee’s heart beats 400 times a minute–when active or excited, this rate is doubled. It even blinks over 40 times every minute.

In spite of its adaptations to the cold and its apparent liveliness, the chickadee has a life expectancy measured in months, not years. Each pair lays 6-8 eggs each spring, but the total number of chickadees stays pretty much the same from one year to the next. Picture windows and predators take a heavier toll than weather.

Chickadees probably mate for life, but a bereft bird will take a new mate eventually after its mate dies–females have been recorded replacing their mate three times in a single season. But if a chickadee does survive its first year, its life expectancy goes up sharply. Some banded birds have lived for over 12 and a half years, cheering Northlanders through the dreariest of winters.

(Recording of a Black-capped Chickadee)

This is Laura Erickson, and this program has been “For the Birds.”