By Judy O’Gorman Alvarez
SANDY HOOK – Take the flight of the tiny golden-crowned kinglet. It’s small and delicate, but hardier than you might think.
And, if Tom Brown’s bird-banding project here at Gateway National Recreation Area is successful, this 5.2-gram bird, who weighs less than a quarter, will offer us more information about migratory birds that fly through this area as the result of the new, delicate metal band he is now sporting on his leg.
Brown, a bird-bander and field biologist at the College of Staten Island (CSI) on Staten Island, N.Y., makes it his business to study migratory birds and their eating and mating habits on this 7-mile barrier spit. The best way to do that is to briefly capture them, record data about them, outfit them with tiny aluminum bands and then gently release the birds back into the wild.
Most weekends from mid-September to early December – and again in spring – Brown, who lives in Middletown, sets up nets at Sandy Hook and spends hours catching mostly small birds for his study.
A good number of migrating raptures, shorebirds and songbirds are attracted to Sandy Hook because of its location and food. “It’s a great stopover site for migratory land birds,” he says.
At the end of each season, Brown sends his data to the U.S. Fish and Wildlife Service’s Migratory Bird Program. The program monitors the status and trends of various species and their habitats as they head south in late summer and fall and again in the spring when they travel north. Some species will go as far north as the Arctic, and later in the season, some species travel as far south as South America.
The banding program keeps track of information on population, geographical distribution, the condition of the birds’ breeding and wintering habitats. All that data helps the wildlife service with responsible management and to provide or protect conditions for the birds, according to the wildlife service website.
“Banding is a good way of sampling, especially songbirds, who are so mobile,” says Brown, whose research is financed by CSI, with an occasional research grant.
Although he has a few graduate students helping out, he works most days on his own.
“Really, the only way to get data on populations is to catch and band them if you want to look at survivorship and longevity.” He points out longevity is how long the birds are living, survivorship is an estimate of a population.
Brown grew up on Staten Island, “the old Staten Island,” he says, when the island was flush with wooded areas and as a result, a variety of birds.
“We grew up playing sports and hanging out in the backyard watching the wildlife.”
He went on to graduate from the College of Staten Island (CIS) and City of New York (CUNY) graduate school. He then returned to CIS, where he has been teaching for the past 21 years.
Most weekdays Brown spends time in the classroom teaching field or behavioral biology and supervising student labs. On weekends in fall and spring, armed with what looks like a fishing tackle box filled with metal bands in sizes fit for the littlest to the biggest birds, Brown mans one of CSI’s five banding sites, one each at Sandy Hook and Fort Tilden in Queens, N.Y. and three on Staten Island.
Whether he’s catching a tiny 22-gram white-throated sparrow or a large Cooper’s hawk with a wing span of 3½ feet, Brown holds them gingerly in his bare hands as he bands them.
On a recent day, Brown measures the golden-crowned kinglet, barely larger than a hummingbird, checking its wingspan. He places it in a film canister to keep it steady on a small scale in the trunk of his car while protecting it from the Sandy Hook winds. The different colors of the feathers tell him the bird’s gender and, if wear-and-tear marks on the wings or the bird’s eye color doesn’t tell him its age, Brown says feeling the top of the bird’s head can give him a clue. Like a baby’s head, a soft fontanel indicates the bones of a young bird’s skull are not completely formed.
During their spring travels, the golden-crowned kinglet flies from Maryland or Virginia to the Adirondack Mountains and even as far north as Canada, a prime mating area for those birds in June or July.
Brown says occasionally he’ll capture a bird that was banded elsewhere on the East Coast, but most times he meets birds who have never been banded or ones that he has banded before. “Many birds we catch year after year during breeding season because they’re returning to the same breeding spot.”
A banding project like this one is valuable to researchers, according to Brown.
“With a bird in hand you get so much information as opposed to seeing them through binoculars in a nest,” he says. “There’s a lot of data (to be gained). You can look at demographics – age ratios, male to female ratios – you can’t get unless you have the bird in hand.”
Brown says even when he spots a bird during breeding season he can’t be sure it’s breeding unless it’s examined carefully to see the physical characteristics. “A female will lose the feathers on her belly while incubating eggs,” he says.
“Capturing these birds gives us the data we can’t know by simply seeing them in the field,” he says. “Putting tags on them help us look at the birds’ migration routes.”
The capture, data recording and banding take less than 5 minutes. Brown then slowly opens his hands and the bird is sent on its way.