WASHINGTON — Washington. -- Get along with you, little flame-like bird, you're late. Summer slipped by weeks ago, and now your food sources of gerardia and honeysuckle are drying. Only a lingering blossom of phlox or cardinal flower can offer you that drop of nectar you need to energize your whirring wings. You're the last hummingbird to circle the sugar-water feeder, that strange attracter where many of your species zoomed in parabolic splendor this summer. They have gone, and only you, heading down from the north, poke at its viscous liquid.
Speed well, little buzz-bomb. The chilled north winds stream right behind you, draining all colors and life from your nectar-bearing flowers. Suck all the energy you can into that tiny less-than-an-ounce frame to carry you through the gardens of southern Virginia, the Carolinas, Georgia and then across the 500-mile expanse of the Gulf of Mexico into your winter quarters of Mexico or the Yucatan.
You've spent all summer long playing and arguing in the fields and gardens of the north. With wings beating some 80 times per second, you have the fastest-paced metabolic rate of any
animal. You need an ounce of honey nectar each day, just to exist, but you recklessly burn up its energy with your pugnacious behavior, fighting off your own species from the feeder, chasing male and female in exhausting pendulum flights, swinging back and forth defending your territory.
Now it's autumn and you should be well on your way south.
Why do you males expend your energy in such aggressive behavior? You're too tiny and handsome to be such a bully. But your male hormones drive you to stake out your territory in spring and defend it from nearby twigs from which you survey your domain like an emperor. You chase practically everything moving near the feeder -- even confronting the white-faced hornets with their deadly sting.
I've never watched a nuptial mating, but I understand you do it with almost as swift and transient a swoop as you exercise around the feeder. Is your love behavior just another sign of aggression? And once you've mated, your female goes back to her nest which she has built without you, lays two eggs, and broods over them. You go back to your perch where you continue your endless swinging back and forth, buzzing friends and foes that dare approach your feeder. According to bird watchers, you have nothing more to do with her or your offspring. Male chauvinist!
Now, young cock of the air, a recent report suggests that your feisty behavior keeps you lean as well as mean, and hence you weigh significantly less than the female of your species. This may lead to a fatal energy crisis with you, especially during storms or some cool autumn night when the temperature dips and you cannot keep warm long enough to greet the next sunrise. Or perhaps you won't have that extra energy you need to propel yourself across the watery desert of the Gulf.
Hurry up, you fierce fluff of energy; fatten yourself on sugar-water from the depleted feeder and nectar from the drooping flowers. Speed along, across the south, over the gulf. Your drive for survival shines as bright as your ruby throat.
Barbara Tufty is a science writer and consultant.