On the Trail of a Fleeting Subject
Wednesday, December 14, 2005
David W. Holmes backed his station wagon into the driveway of a Calvert County home yesterday and popped open the hatchback so his trapping partner could pull out the bird cage. A hummingbird had been seen there, and Holmes wanted to get his hands on it.
He wasn't surprised that a tiny tropical creature would be zipping around the Washington metropolitan area on a windy morning with temperatures in the mid-20s. The licensed bird-bander had already had placed numbered bands on the legs of three others in suburban Maryland this month as part of research into why and how hummingbirds spend the winter in this area. Some experts think the population of East Coast wintering hummingbirds is growing and hope the study will prove their theory true.
A hummingbird sighting was thrilling enough to have attracted a parade of visitors after the news went out on a birding listserv last week. Two men and a woman had scouted the bird unsuccessfully with binoculars and a spotting scope for half an hour before Holmes, a 65-year-old music teacher, and Bruce Peterjohn, a 53-year-old biologist, arrived in North Beach.
The men, who are serious amateur ornithologists, took down the nectar-filled feeder on the home's front porch, hung it inside their bird cage and set it on a card table. As Holmes ambled back to the station wagon to assemble his tools, the hummingbird zoomed into view, circled the cage and flew inside toward the feeder. The trap door clicked shut.
"I can't believe it," Holmes muttered. "Definitely not ready."
He knelt by the open hatchback, moving rapidly because he knew the captured bird would be terrified, which can be fatal to hummingbirds. With ungloved hands, he cut and shaped an aluminum alloy band, so small that he stores them on a safety pin. He read out the number -- N87604 -- and Peterjohn recorded it on a data sheet. Then Holmes retrieved the bird, which was slamming itself against the cage in its anxiety to get out.
"Good grief," said Holmes, cupping the iridescent bird in his hand as puffs of feathers blew into the air. The hummingbird was molting, but stress also can cause feathers to fall out. Delicately, Holmes placed it in a black sock to calm and warm it, took it back to the car, then wrapped the band around its leg. He could feel its heart beat.
With a magnifying jeweler's loupe, he measured the bird's wing, tail feathers and bill with a caliper, calling out the measurements for Peterjohn to record. Seeing the bird up close, looking at the color and width of its tail feathers, they could tell it was a male rufous hummingbird, born this year.
Rufous birds, named for their reddish color, nest in the Northwest, and most spend the winter in Mexico. But within the past two decades, people who left their feeders out in cold months began seeing them in Eastern states. At least three have been banded this decade at a Smithsonian Institution garden in downtown Washington. A bird banded in Richmond several years ago turned up in Montana the following fall, then was captured in Richmond again the next winter. The Calvert County bird banded yesterday was not the first for homeowner Jim Stasz, who had another at his feeder a decade ago. By late January, most or all will leave for warmer places.
"They used to be considered lost," said Bob Sargent, founder of the Alabama-based Hummer/Bird Study Group, which is coordinating much of the winter hummingbird research and training most hummingbird banders, including Holmes. "That's just not true. These birds are here by design. They are doing what their genetic makeup tells them to do."
Sargent believes the Eastern winter hummingbird population is growing, either because the birds are being helped along by backyard feeders or because they are reproducing more rapidly than other hummingbirds. Winter hummingbirds also eat insects when it is warm enough that they come out.
Hummingbirds weigh about an eighth of an ounce. Holmes had forgotten to bring his scale -- "How did I do that?" he reprimanded himself -- but could tell that the bird had no body fat. That is normal, he noted, because hummingbirds bulk up during the day, eating their weight in sugar water, and slim down while in a sleep-like state overnight.
But this bird suddenly seemed too still. Its bill gaped. "Oh, dear, what have we done?" Holmes, who has banded birds since 1970, recalled thinking.
He sped back to the porch and held the hummer up to the feeder. Peterjohn leaned over the bird, hoping his breath would revive it. "Take him inside," Holmes said. "Get him at least warm."
After a few minutes there, they decided the blast of the car heater was a better solution and rushed back to the station wagon. Inside the hot car, the bird gradually perked up.
When Holmes emerged, the hummingbird was pushing against his hand, struggling to get away. He opened his fingers, and it bolted. Within a few minutes, it settled on a second nectar feeder in the front yard.
"It turned out to be more interesting than I wished," Holmes said later, sitting in his car. "The standard fear is that you are going to hurt them. Birds are delicate, but they are delicately strong. They go through an awful lot in the wild."