Birds have adapted over millions of years to deal with the killer weather upon us now. Let’s talk about small birds, your feeder birds.
They don’t need warm hats and mittens. They need food.
Shelter at night, which they find on their own in cavities or thick evergreens, is critical. But fuel to keep them warm is foremost. Bird engines run at high rpm, so to speak.
Chickadees and other small birds need to eat and eat and eat.
Small seeds are easier for birds to process. So are seeds without shells. Black oil sunflower is sold in this form.
Golden safflower, another popular seed, is high in protein and fat, and has a thin shell easier for small birds to open. (It also is said to be unattractive to squirrels!)
In colder weather larger seeds are said to be a more efficient source of energy. The chickadees visiting our feeders tend to take a seed and fly to a nearby perch to eat. Flight takes energy. Fewer flights would be less costly.
Meal worms, fresh or frozen, are an excellent source of protein and fat.
Suet pellets, about the size of a grain of rice, are available. There are pellets mixing suet and ground meal worms.
Golden safflower seed is popular because it has high protein and oil content contained in a thin shell, easier for smaller birds to open.
Water is very important in cold weather. Liquid water is difficult to find in sub-zero temps, even though the sun once again has warming power.
At our feeders this morning, Wednesday, temp minus-28.9, the first American Goldfinch to visit us went directly to the heated bird bath (which had a thin crust of ice that I removed).
Small animals need more energy to stay warm because they lose more heat than do large animals. Being small in weather like this is no advantage.
It is a matter of ratio, the amount of surface opposed to volume.
The Cornell Lab of Ornithology explains it this way. Consider a chickadee as a one-inch cube. Surface area is six square inches. Volume is one cubic inch.
Now, a turkey, which we will call a two-inch cube. This has a surface area of 24 square inches, a volume of eight cubic inches.
The chickadee has a surface to volume ratio of 6:1. The turkey’s ratio is 24:8 or 3:1.
The chickadee, with more surface from which heat can escape in relation to its volume, will lose more heat than the larger bird. The chickadee must frequently refuel it furnace.
Chickadees maintain, as do most songbirds, an average body temperature of 105º.
They have a resting heart rate of over 500 beats per minute. That, by the way, is 3.26 billion beats in a lifetime of 12 years. Your heart, if you live to 70, will beat 2.5 billion times. Generally, the smaller your size, the faster your heart beats.
Chickadees have a breath rate of 65 per minute, one inhale per second.
Chickadees must eat a third of their weight each day to maintain life. Chickadees weigh .36 ounces. A penny weighs .088 ounces. Four pennies per chickadee.
A small bird will digest its food in as little as 30 minutes. It might retain some food in its crop to eat after it leaves your feeder.