Winfield ? Eight feeders stand brimming with sunflower and thistle. Below them, a carpet of assorted seeds covers Max Thompson’s backyard.

A birdbath heated to just the right temperature for drinking or taking a dip sits nearby. Yet amid this paradise for songbirds are two nearly invisible nets where thousands of birds have become entangled through the years.

Within minutes they have been freed from the mesh and, with a tiny metal band on one leg, they have flown off as part of a worldwide research project.

Thompson, a retired biology professor at Southwestern College, said banding was a great way to gather migration and biological information on species ranging from hummingbirds to bald eagles.

Biologists have been affixing tags to migratory birds for more than a century. Each band contains an identification number. When found, the number is checked within a federal registry to learn the banding location and date plus the bird’s age and gender.

Though biologists may attach more than a million bird bands a year, very few end up getting reported, especially on songbirds. Return rates on many banded songbirds, including goldfinches, are below 1 percent, according to the U.S. Geological Survey.

Max Thompson uses a magnifying glass to read a band attached to a bird's leg in Winfield.

“It’s like finding a needle in a haystack,” Thompson said. “If one doesn’t drop dead in somebody’s yard, they’re usually not found.”

Trends and surprises

Still, during almost 40 years of banding, Thompson has attached enough “needles” to get some amazing returns.

He has had a yellow-billed cuckoo banded in Kansas found in Brazil, and Cowley County warbling vireos reported in Guatemala and El Salvador.

His nets also reveal trends. Thompson has seen a spike in house finches this winter. Most years he sees songbirds in numbers that would surprise most Kansans.

Several years ago, with the help of a friend, Thompson banded 189 birds around his feeders in one day.

Last winter, he put first-time bands on about 800 goldfinches. Last month, he banded 481 birds, mostly goldfinches, with 43 recaptures.

Every walk to the net could hold a surprise. On Feb. 9, he caught a goldfinch he had banded in 2000.

“That’s pretty old for a small bird,” Thompson said. “People used to think two or three years was good, but they’ve started to rethink that. A friend in Arizona trapped a hummingbird she’d trapped nine years before. Without bands, it would be hard to figure that out.”

Thompson said he keeps the bird’s safety in mind and seldom nets when it’s much below freezing.

“Birds are pretty hardy, but they can’t keep warm when their feathers get compressed in a net,” he said.

Sometimes he will place a bird in a coat pocket for a few minutes, or place it in a cloth bag with other birds and bring it inside to warm.

He’s also careful when untangling a bird from the nylon netting so tiny wings or legs aren’t strained or broken.

“It’s not that bad,” Thompson said as he deftly separated a ball of mesh and feathers. “I’ve had helpers try and give up, then I’ve come over and undid it quickly. Experience helps.”

Handled with care

His experience showed on a late February morning, when hoarfrost covered the two nets that reached from the ground to about 8 feet high.

Visibly coated in ice, scores of birds flitted over and around the nets that have sagging pockets to entangle the birds.

Sitting at a desk, watching out a huge window, Thompson patiently eyed the thermometer. Around 9:15, he said: “It’s up to 35.5 degrees. That ice should start falling off any minute, and we’ll start getting some birds.”

At 9:30, Thompson plucked six tangled goldfinches from the nets, carefully placed them in a cloth bag and took them into his nearby garage.

There, he checked for the developing yellow plumage of males, and small wing feathers to see whether the bird was mature or hatched last spring.

Thompson carefully crimped a band around one leg, doubled-checked the facts he had recorded, then let the bird fly.

Fifteen minutes later he took six more from the net. One wore a band Thompson had affixed a few weeks earlier.

He will keep the backyard nets up for a few more weeks, until songbirds start migrating north.

He admits he does it for more than just science.

“I kind of love it,” Thompson said. “I never get tired of it. It’s a lot of fun.”