They flash in front of flowers and feeders for seconds, their wings a blur, and then whiz away. Next they're back — but before you can gasp at the beauty, they're off again. A glittering fragment of a rainbow; a flaming comet; a living gem: All of these metaphors struggle to describe the evanescent magic of hummingbirds.
But what they are doing when we don't see them is more wondrous yet — as I discovered several years ago. Working with a licensed wildlife rehabilitator, Brenda Sherburn, I was privileged one summer to help feed, raise, and release orphaned hummingbirds.
Too often, people "rescue" baby hummingbirds prematurely, Sherburn told me. It's rare to find a hummingbird nest, but if you do, back off, leave the babies alone, and, using binoculars to watch from a safe distance, observe the nest without looking away for at least 20 minutes. "So few people can just sit still and watch anything that long," said Sherburn. But if you so much as blink, you could miss the mother's return. A mother hummingbird leaves the nest from 10 to 110 times a day to find food for her nestlings.
To survive, a hummingbird must consume the greatest amount of food per body weight of any vertebrate animal. A single bird may drink its own weight in a single visit to your feeder — and seconds later, come back for more. That's because they breathe 250 times a minute. The resting heartbeat is 500 beats per minute, and the heart can rev to 1,500 a minute in flight. A film I watched claimed that a person as active as a hummingbird would need to consume 155,000 calories a day — and the human body temperature would rise to 700 degrees Fahrenheit and he or she would ignite!
An adult hummingbird visits an average of 1,500 flowers in a day. If the nectar were converted to a human equivalent, that would be 15 gallons a day. But few people realize that insects are equally essential. Each hummingbird needs to catch and eat 600-700 bugs a day. (So spraying insecticide in your yard is like hiring a hummingbird exterminator.)
The food requirements mentioned above are for a single hummingbird. A mother caring for nestlings (there are usually two) needs even more. Lucky for us, Sherburn had access to a fine compost pile with plenty of fruit flies, and her husband, Russ, was willing to catch fresh ones for us every day.
Each morning, when normal people were grinding coffee beans, Sherburn would take out her mortar and pestle to grind flash-frozen fruit flies. Then she'd mix them with nectar, vitamins, enzymes, and oils. Because this food spoils easily, we had to make a fresh batch several times a day. From dawn to dusk, we would deliver this to the babies' gaping beaks — by syringe — every 20 minutes.
Sherburn was one of a handful of specially trained and deeply committed wildlife rehabilitators qualified to do this. I was honored to help. But for these fragile nestlings, each moment was fraught with danger. Miss a feeding and the babies could starve. Worse, she explained, was what could happen if you feed them too much. "They can actually pop," she told me.
Hummingbirds are little more than bubbles wrapped in feathers. Our bodies are filled with organs; theirs are full of air sacs. Their feathers weigh more than their skeletons, and both their bones and their feathers are hollow. It's hard to imagine anything more fragile.
And yet our fragile orphans, like the hummers at your feeder, were born to conquer the sky. Sherburn lives in California, which is home to several species; as their feathers grew in, our babies revealed they were Allen's hummingbirds. To impress a female, a male Allen's performs a plunging flight that makes it the fastest bird for its size in the world. In terms of body lengths per second, it even beats the space shuttle.
Here on the East Coast, we have only the ruby-throated hummingbird, named for the flaming red throat patch on the males. These birds are equally spunky: Each fall, they undertake a punishing migration across the Gulf of Mexico, which may demand 21 hours of nonstop flight.
It's shocking to realize that something that hatches from an egg the size of a navy bean is capable of such a feat. But equally shocking is the gauntlet of dangers a hummingbird may face on an average day. Hawks, jays, squirrels, crows, even dragonflies eat them. They tangle in spiderwebs searching for insects (they also use the silk in their nests, to allow them to stretch as nestlings grow). They fly into our windows; they're hit by our cars; they're poisoned by our pollutants. The most common reason for any bird's admittance to wildlife rehab is also our fault. It's abbreviated on forms as CBC: caught by cat.
And yet, we can help. Put out a feeder. Plant nectar-rich flowers. Keep a compost pile. Support a wildlife rehab center.
Reasoning that surely a bird so tiny with feathers so brilliant must be born anew each day, the Spaniards who first encountered South America's hummingbirds called them "resurrection birds." This names the gift these birds offer us this summer, with each fleeting glimpse. They force us to see the world made new each time, and teach us to believe in ordinary miracles.
Sy Montgomery is a naturalist and
an author. Send your questions about animals to syandlizletters@gmail