Although the creatures are common in Maryland and may be found readily in the spring in urban backyards, many people have never seen them -- or perhaps have mistaken them for large insects.
The animal is the ruby-throated hummingbird -- the only one among 339 known species of the tiny bird that inhabits Maryland -- and area residents soon will have a chance to learn how to find and photograph it.
The world's most dedicated watchers of hummingbirds, and pTC likely the only couple who can claim to make a living off the little bird, Robert A. and Esther Quesada Tyrrell of El Monte, Calif., will present a slide-lecture Dec. 2 at the Baltimore Zoo.
Mr. Tyrrell, 43, said he saw his first hummingbirds while vacationing at the Grand Canyon in 1975, but did not seriously consider the problems involved in photographing them until a backyard encounter later that year.
"I happened to be in my parents' backyard, and I saw a hummingbird silhouetted against the sky on a telephone wire. It was just sitting there. I thought how nice it would be to photograph it hovering in the air."
Mr. Tyrrell, a professional photographer at the time for a studio with clients including several major league sports teams in Los Angeles, borrowed some equipment and set it up in the yard at 6:30 a.m. to catch some hummingbirds in flight.
The project took 2 1/2 hours, and the pictures turned out just fine -- except for the wings. They were "blurry," Mr. Tyrrell recalled in an interview.
The next project took six years -- producing pictures of hummingbirds in flight with their wings frozen still.
The problem for photographers is that hummingbird wings beat approximately 78 times a second -- so fast that the human eye cannot see them, and the camera can almost never freeze their movement.
Mr. Tyrrell said the solution was an antique piece of lighting equipment: a 1940s-vintage strobe that flashes at a 50-millionth of a second, enabling him to stop the bird in flight.
"That's what freezes the bird in flight," he said "It's not the film speed or the shutter on the camera. It's the actual flash unit."
Over the past decade, he and Mrs. Tyrrell, 41, have devoted increasing amounts of time to the pursuit of hummingbirds. They photographed and studied the habits of all 16 species that thrive in North America and compiled their work in a glossy hard-cover book, "Hummingbirds: Their Life and Behavior," published in 1985 by Crown and selling for $35.
The book proved popular enough -- with 11 printings and 100,000 sold to date -- that the Tyrrells were able to give up other jobs and make hummingbirds a full-time effort.
It has kept them well stocked with film and airline tickets to continue what they called their "treasure hunt" in more tropical climes. The result is their just-published second book, "Hummingbirds of the Caribbean" (Crown, $40), featuring 16 more species. There are 236 color photos, culled from 10,000 images in Ektachrome 100 slide film.
The Tyrrells say the biggest challenge was tracking down the smallest of the 16 Caribbean species and world's smallest bird -- the bee hummingbird. It is found in Cuba and, weighing less than a penny, is the easiest to mistake for a bug. They had to haul their equipment through a crocodile-infested swamp to find it.
Maryland's ruby-throated hummingbird, the only species east of the Mississippi, is easier to find.
The bird's size ranges from 3 to 3 3/4 inches. The male has a sparkling scarlet gorget, or neck pouch, a green back, gray-white underbelly and forked, brownish-black tail. The female does not have the brightly colored neck, and its tail is rounded and marked with white spots.
To attract them, set out special feeders filled with a solution of one part sugar to four parts boiled water, which approximates the nectar the birds normally sip from flowers through their long bills. A drop of red food coloring also helps get their attention.
Don't be surprised if you see hummingbirds battling over feeder territorial rights. They can be fiercely combative, and the Tyrrells note that about the only time hummingbirds get together is for a few brief seconds -- to mate.
The bird sleeps at night, and the best time for observing them is early morning and late afternoon, Mr. Tyrrell says, "for the simple reason that is the height of the feeding times when they first
wake up in the morning and feed heavy for three hours, and before they go to sleep they have to store energy for the cold night."
The hummingbird arrives in the region around mid-April and nests primarily in May and early June. When cold weather nears, the hummingbird migrates south to Florida or Central America.
The Tyrrells, too, having finished off hummingbirds of North America and the Caribbean, plan to head south -- to South America, and the 300-plus other species.
"I'm going to have a beard right down to the floor when I'm done," Mr. Tyrrell said.
The Tyrrells' slide lecture, "Hummingbirds -- Jewels of the Sky," will be presented at 2 p.m. Sunday Dec. 2 in the Baltimore Zoo's Maryland Building.
Admission is $3 for members and $4 for nonmembers. Because seating is limited, advance reservations are recommended and may be made by calling the zoo's education office at 467-4387.