For the Birds Radio Program: Hummingbirds
One of the great joys of life in the northland is watching hummingbirds. It’s possible to see dozens in a single backyard if you have enough feeders set out. You‘11 get more hummingbirds by setting out four or five cheap little one-spout feeders than you will with a beautiful, expensive six-spout one, because these spirited little sprites spend so much of their time chasing one another away.
Hummingbirds belong to a family of avian superlatives. Their family includes the smallest bird on the planet (the Bee Hummingbird, 2 ½ inches from the tip of its beak to the tip of its tail), several species with the fastest wing beats (over 60 beats a second) and heart rates (1260 beats per minute in the large Blue-throated Hummingbird, even faster in tinier species), and the only birds that can fly straight up and backwards.
So many people describe hummingbirds as jewel-like that it is as much a cliche as an apt description. These birds are so tiny and their colors so brilliant that many of the ornithologists who first beheld them in earlier centuries named them for emeralds, sapphires, amethysts, garnets, and of course rubies. The pigments of their plumage are actually dull, dark gray and green, but the outer layers of cells of the feathers are arranged to be iridescent. A ray of light hitting a male’s throat at the right angle is breathtakingly dazzling.
Our Ruby-throated Hummingbird, the only hummer normally found in Minnesota and Wisconsin, is here only from spring through fall. Traveling from the northland to Central America and back again every year is amazing enough for large birds. It seems nothing less than a miracle that hummers routinely accomplish this, especially when you consider that each one weighs less than two pennies. Young birds, completely on their own, work their way down to Texas, and then after fattening up, strike out straight over the Gulf on Mexico toward the Yucatan Peninsula. They each travel a minimum of 600 miles over water, where there is no place to land or rest, during hurricane season. The oldest known Ruby-throated Hummingbird lived to be at least 9 years and one month, and so must have made that migratory journey 18 times during its life.
It makes sense that our hummingbirds weigh in at about two pennies worth, because every one of them seems to want to get its two cents in. They chatter at one another and at other birds, squirrels, dogs, and us. They have an intelligence worth reckoning. Many people suspect that their backyard hummingbirds actually recognize them personally, peeking in at the windows to complain when a feeder goes dry. Research supports their surprising intelligence, making us wonder at how so tiny a brain can be filled with such a large measure of curiosity, feistiness, and memory.
Hummers live high-powered lives, expending what seems like far more energy defending their perches at feeders than they could possibly be getting back in usable calories. Of course, scientists have done countless studies probing into hummingbird intelligence and energetics, and produced all kinds of calculations about metabolic rates and the ratio of energy consumed to energy expended. But calculations hardly tell the whole story. As Walt Whitman wrote:
You must not know too much, or be too precise or scientific about birds and trees and flowers and watercraft; a certain free margin, and even vagueness-perhaps ignorance, credulity-helps your enjoyment of these things.
Fully a third of the weight of a hummingbird is in the pectoral muscles that power its wings, and I suspect that much of the remaining weight is testosterone. I watched a hummer attack a Bald Eagle once, diving fiercely toward the eagle’s upper neck and back again and again. A Bald Eagle outweighs a hummingbird about 1600 times, and I don’t think this eagle even noticed the little twerp, but once he had left the hummer’s airspace, the tiny bird zipped back to his perch and chattered excitedly about his success. Looking into those tiny black eyes fired with intelligence and exuberance, I marveled at the biological processes that can transform nectar and bugs and ¼ cup of processed granulated sugar mixed with I cup of water into such magical energy and brilliant beauty. When the Wicked Witch of the West, doused by a bucket of water, was melting, she lamented, “What a world! What a world! I look at hummingbirds and I rejoice. What a world! What a world!