Darting, Hovering 'Jewels of the Air'

DARTING HOVERING 'JEWELS OF THE AIR' An Introduction to Arizona's Hummingbirds

Late in the summer, I decide to wash the kitchen windows. So I climb onto the counter and take a knife to the old paint spatters, preparing to apply some blue stuff to the glass. That's when she appears.

She is a hummingbird, a pert lady of vague ancestry, probably the species called Anna's. She flies up to the feeder hanging from the eaves outside the kitchen window and takes a position at the post nearest me. We peer at each other, eye to eye. She turns her back, iridescent green in the afternoon sun, and takes a long, leisurely drink, pausing every third or fourth sip to back off about an inch, swivel 90 degrees on her vertical axis, and glance curiously at me. She hovers motionless except for her buzzing wings, a near-invisible blur at 52 beats a second.

I hold my breath in awe. Absurd! When she arrived, my blade was screech-

ing over the glass. If that racket didn't scare her off, no small move of mine will. Does she realize she's just a forearm's length away? Does she know the clear glass bars me from reaching out and snatching her? Does she care? Sated, she turns lazily to face me full on. Her lustrous jet eyes seem to show the same sense of wonder I feel. For several long seconds, she stares at me, and then, as abruptly as she came, she shoots away, disappearing against the verdant backdrop of the neighbor's citrus trees.

Such mini-adventures occur every day in Arizona. Eleven different hummingbird species visit our state regularly. Four species are seen irregularly, and one more is "accidental," meaning the species wanders north of the Mexican border on rare occasions. By contrast, only one species, the ruby-throated hummingbird, breeds east of the Mississippi River, and only a few others migrate through the Great Plains.

Arizona serves as a corridor for migrating hummers as they journey between breeding grounds as far north as Alaska and winter homes in Mexico and Central America. The canyons and mountains of southeastern Arizona mark the extreme northern range for exotic tropicals with tantalizing names like "berylline," "violetcrowned," and "blue-throated," and at least one crimson-helmeted breed, Anna's, has taken up permanent residence in the Sonoran Desert.Not many birds put on a better show than the hummers. They hover; they fly backward; they turn backflips in the air. They are virtually without fear. They will land on your shoulder or perch on a finger held up to a feeder. Naturalists strolling through forests or desert canyons have had hummingbirds accost them to examine a red necktie or bandanna, evidently hoping to find a large flower attached to the human.

Ferociously territorial, especially during mating seasons and migrations, hummers seem to relish a good fight. "Where do passions find room in so diminutive a body?" wondered the 18th-century author and farmer J. Hector St. John de Crèvecoeur. The irascible cock stakes out a claim by occupying the highest perch he can find and announcing himself with a raucous crow, a prolonged grating noise that sounds like someone grinding a pair of glass marbles together. Any intruder risks a furious attack.

"I think they enjoy fighting with each other," says Tom Collazo, caretaker of The Arizona Nature Conservancy's Ramsey Canyon wildlife sanctuary. "It's their greatest pastime." Hummingbirds will take on almost all comers. I have seen one swat a cat to drive it off the window ledge beneath a feeder, and hummers chase away marauding finches. Sally Spofford, a retired Cornell University ornithologist who now lives in the Chiricahua Mountains, recalls once seeing a blue-throatdrive a pine sisken "right to the ground." Rufous hummingbirds are especially pugnacious as they pass through Arizona. "I think of the rufous as a little fighter pilot," says Dr. Spofford's husband, Walter, also an ornithologist. "He just zips around after everything."

This matter of aggression was so intriguing that I tracked down Professor William A. Calder III to ask him about it. He has studied hummingbirds for the last 17 years, and every bird expert with whom I spoke referred me to him. When I caught up with him in his basement office at the University of Arizona, I found a slender man whose alert, confident demeanor subtly brings to mind his subjects.

During the mating season, Calder says, only the males are territorial. "The females sit the nest. They'll go and feed, but they can't fool around with claiming something and making a big deal out of it." When migrating time comes, though, all hummers-male, female, and immature-go into fierce battle. Each hummingbird must claim enough ground to provide food to refuel for the marathon flight's next leg. "It's every bird for himself," says Calder. "There's no idea of family-only the individuals survive."

Unlike some birds, hummers never form permanent breeding pairs. Still, the male must go to quite some lengths for a one-night stand. Allen's hummingbird is a classic example. He performs a spectacu-lar mating dance, designed to dazzle the object of his affection with his gleaming colors and stylish flying technique.

Orienting himself so that the sun shines on his radiant head and neck feathers, he soars sixty or a hundred feet into the sky and then drops straight down in a dramat-ic J-shaped swoop. In the similar dive of an Anna's hummingbird, he emits a shrill, metallic cry as he reaches bottom. Allen's, a green bird with a bright orange throat and white breast and belly, arcs back and forth in front of the female several times before he begins his climb.

The J swoop frightens off competing males. Another dance, called the "shuttle," has the male swing before the female in eight or teninch-wide sweeps while he sings or vibrates his feathers impressively. It is the mating dance.

The female lays two eggs in a tiny, fluffy cup fashioned of spiderwebs and soft fibers such as cottonwood silk. "It's a beautiful little nest," says Calder. He rummages in a cabinet and pulls out a hinged plastic sphere holding a golfball-size nest attached to a conifer twig.

When he opens the display, we can smell a piney forest scent. The inside is lined with soft, white cottony tufts. So neatly does the outer surface blend with the spruce branch that the nest could be some growth on the tree.

"They decorate it with lichens and moss, which serve as a camouflage," he explains. "It's all put on by little spiderwebs, these strands"-he indicates the minuscule guy wires that hold the nest in place. "It's built underneath something, to shield them from the sky. The night sky above breeding grounds in the northern United States, Canada, and Alaska is extremely cold. The air temperature near the ground might be above freezing, but the night sky above the warmth-holding canopy of vegetation can be minus 20 degrees centigrade." He does a quick mental calculation. "That's four below zero, Fahrenheit.

"If there's a branch above them, a predator can't see them; rain can't get them; hail can't get them; snow can't get them."

When the female can't find a branch directly below another, she will build the nest off to the side, cantilevered to line up with a sheltering branch. "There's an amazing amount of flexibility in their behavior, to get it just right," comments Calder. Hummingbirds may nest anywhere from a foot off the ground to 40 or 50 feet up in a tree.

After 15 to 22 days, the eggs hatch. The babies stay in the nest 21 to 31 days and, after they are fledged, the mother may continue to feed them for another month. During this time, females of some species may start another brood. Some even build a second nest for the new family.

Once the youngsters are coaxed out of the nest, the birds take off on their

A sampling of the most colorful of Arizona's hummingbirds.

survival device. Calder, the first scientist to record a nesting hummingbird's torpor, explains that it is a way of "turning down the thermostat" to conserve energy. "The smaller an animal is," he says, "the faster its turnover time for energy. Everything is on a compressed time scale when the creature is small. Eleven or twelve hours of night is a long time for a little hummingbird." If it goes torpid, its remaining energy will last through a winter's night, leaving the bird with enough fuel to get to the flowers in the morning.

The trait helps explain how such a fragile, tropical-looking creature can weath er surprisingly severe conditions. Sally Spofford has reported both blue-throated and Rivoli's hummingbirds that overwintered in the Chiricahua Mountains when temperatures dropped to 20 degrees below zero, Fahrenheit.

The Hopis call the hummer Tocha and made it one of their favorite kachinas, a spirit messenger between the sky and the earth. For the Navajos, it is a bringer of rain; to the Apaches, it brings good tidings. The Aztecs named it Huizitzil and believed their dead warriors came back as hummingbirds to fight off the nighttime darkness so the sun's light and warmth could triumph at dawn.

Whatever you call the feisty, brilliant little fighter, he graces the home that makes him welcome. He is a bringer of good tidings, indeed.

Selected Reading

Hummingbirds, by Crawford H. Greenewalt. Doubleday, New York, 1960.

The Way of the Hummingbird, by Virginia C. Holmgren. Capra Press, Santa Barbara, California, 1986.

Hummingbirds: Their Life and Behavior, by Esther Q. Tyrrell, with photographs by Robert A. Tyrrell. Crown Publishers, Inc., New York, 1984.

A Field Guide to Western Birds, by Roger Tory Peterson. Houghton Mifflin, Boston, 1961.