A magnolia warbler hung in a mist net strung between poles in a copse of goldenrod. Bob Mulvihill found it Friday on his 9 a.m. rounds of Michael and Barbara Becich's property in Bradford Woods.
He carried it in a pouch back to the patio where a small group had begun assembling before dawn.
"Who wants to see a warbler?" he asked.
Nikki Becich sharply drew her breath; her eyes got big.
No longer than a forefinger, it rested its bright yellow belly against Mr. Mulvihill's thumb and stared from big eyes ringed in white at the Becich family, friends and a small National Aviary crew.
It was the 10th bird of the morning, but a bird in the hand never gets old.
Mr. Mulvihill, the National Aviary's director of ornithology, has spent the past two months showing people in 35 households in the Pittsburgh area how to hold a bird. That's one of the more emotional payoffs for participants in the aviary's Neighborhood Nestwatch pilot project.
It is devised to marry citizen science to a Smithsonian Institution study to understand how human population affects bird behavior and how that behavior differs among urban, suburban and rural settings.
In June, Mr. Mulvihill got Pittsburgh on the short roster of cities that include Washington, D.C.; Springfield, Mass.; and Gainesville, Fla.
The Smithsonian has provided some bands, nets and other equipment and is working on grant proposals to help fund its satellite programs, Mr. Mulvihill said, but "we are going to need to find some funding of our own to reach as many people as we can and to become comparable to the Washington and Springfield efforts." Those sites each have more than 100 households.
The birds of focus are the song sparrow, northern cardinal, Carolina wren, house wren, American robin, gray catbird and all chickadees. These are common to all the study areas. But every bird caught is banded and every bird banded is recorded with an ID number.
The bands come from the Bird Banding Laboratory of the U.S. Geological Survey, which manages a huge data base the Smithsonian information feeds into. The bands come in different colors. Within each species the configurations of colors have to vary so each specimen can be precisely identified.
As Becca Ralston, a teen volunteer at the aviary, began banding a house wren, Mr. Mulvihill told her to put an orange band over a black band on the left leg and a silver colored band on the right leg. That is the only house wren with that order and color of bands.
To get enough rural households to be a viable layer in the study, the study area is within a 50-mile radius of the aviary.
"Within the federal program, the Smithsonian scientists are looking at the effects of density, impervious surfaces and sprawl," Mr. Mulvihill said. "They are looking at survival rates, numbers, diseases, the effects of things like light pollution and ambient noise and at how birds are adapting their culture."
One adaptation, he said, is that city birds have sharpened their pitch to be heard.
Mr. Mulvihill and one or two staff members or volunteers visit each participant's home one day a summer just before dawn to string the mist nets. These are made of an ultra-fine synthetic material that birds can get pretty tangled in without injury.
"Each household gets one visit a year," he said, "so the point is to band as many as possible on that day."
Several times Friday morning, Mr. Mulvihill walked the Becich property imitating a generic bird scold that sounds like "pish." Birders go pishing to roust birds toward mist nets or into view.
The magnolia warbler was just passing through, being neither a nester nor over-winterer in these parts. The Becich family's property of 22 acres is a rich habitat, with bird feeders hung in various places.
Nikki Becich, 22, a recent graduate in biology from Pomona College, was an intern in the aviary's hospital this summer. She will be spending the next eight months in Central and South America working in wildlife medicine and writing for the aviary's blog.
Like Becca, a student at Peters High School, Nikki was a teen volunteer at the aviary. Like Nikki, Becca became an avid lover of birds who also plans to study biology. On a walk to check the nets, Becca bent suddenly, picked something up and stroked it, saying, "Blue jay feather."
Mr. Mulvihill said one of the greatest rewards of Nestwatch is seeing young children become captivated by birds and begin a lifelong interest in them, their habitats and their wellbeing.
Nestwatch participants can watch for the birds whose bands match the ones caught in their yards and log their sightings throughout the winter, but they are not obligated to. More important is the program's resumption in May, Mr. Mulvihill said, "when we'll see how many of the birds have returned."
Most participants in the pilot season had an association with the aviary, among them aviary members Ramona Sahni, a retired physician from Indiana Township, and Larry Sachs, an assistant district attorney from Forest Hills.
"It's a wonderful experience to hold something so delicate and beautiful in your hand," said Ms. Sahni, whose 2-acre yard has been certified as a backyard wildlife habitat by the National Wildlife Federation.
"[The aviary crew] visited me in July," Mr. Sachs said. "I've been watching to see which birds have been back. I'm sure that I'm looking a half hour a day, but it's really more since I watch from the dining room while I eat dinner."
On the aviary's list of birds caught, every bird's weight, wing and tail feather measurement, age, sex, color and fat content are recorded. To see the subcutaneous fat deposits through the translucent skin, blow on the bird's feathers to separate them. Fat recordings indicate whether the bird has fattened up for a long flight away from here or arrived out of gas with the intention of fattening up here.
Nikki banded the magnolia warbler and weighed it, telling Mr. Mulvihill, "Seven and a half."
"All of seven and a half grams," Mr. Mulvihill said.
It's disconcerting to see a wee bird head sticking out of what looks like a choke hold, but expert bird handlers provide a soft shelter within the hand. The horse collaring doesn't hurt them and subdues any belief in escape. It stills the bird and makes banding less distracting.
"If anything is going through their heads, it's, 'Get free,' " Mr. Mulvihill said. "They are not adapted to being scared" being held. "They are adapted to stress. If they're held properly, they just adopt a wait-and-see attitude. They probably see us, if anything, as inconsequential."
The aviary expects next year to continue with the current 35 households and to add about 65 more. To sign up, write to firstname.lastname@example.org with your name, street address and phone number.