Linda Beall sat with a tray of tools in front of her that looked something like implements for jewelry making. Stationed beneath a tent at the Feliciana Hummingbird Festival, the hummingbird biologist fitted numbered metal bands onto birds’ legs, allowing people who catch them later on to determine how old they are and where they came from.

Hummingbirds are passing through Louisiana on their way back to Central America, where they spend the winter. As they happened upon feeders luring them to the festival, held near St. Francisville at the homes of Carlisle Rogillio and Murrell Butler, they inadvertently helped with some research on their species.

People with cameras and binoculars around their necks flocked to Beall’s table as she looked at the birds through a magnifying glass and called out data for assistants to record. It’s a hobby that morphed into a paraprofession for Beall, who said she enjoys learning about birds.

The data she collected Saturday, such as wing measurements, age and sex, goes into a national database that helps researchers learn about migration patterns and breeding productivity of different places along hummingbirds’ migratory paths, said Donata Henry, a biology professor at Tulane University.

Hummingbirds are usually easy to catch, she said. Three of the feeders set up in Rogillio’s yard were inside traps that closed once a bird entered. Assistants then placed the birds in small mesh bags.

Henry’s daughter, 11-year-old Ella Henry, helped fetch the bagged birds for Beall and gave each a name. First up was Bob, whom Beall identified as an adult male.

“Oh, this is a fatso,” Beall said, laughing as she removed him from the bag and started taking measurements. Hummingbirds eat a lot and build up their body fat before flying across the Gulf of Mexico to Central America, she said.

Beall blew through a straw, ruffling Bob’s feathers so she could examine them and look for insect eggs. After banding his tiny leg — so tiny that Beall stores the metal bands on diaper pins — an assistant held the bird near a feeder for one last drink of sugar water before releasing him.

“It’s almost like they enjoy breaking the rules and not flying for once,” Donata Henry said.

Beall and her assistant Deborah Abibou, a bird ecologist at the Woodlands Conservancy in Belle Chasse, answered questions as they worked. They determine age based on the corrugations, or wrinkles, on a bird’s bill — a feature Abibou said is unique to hummingbirds. And the throat feathers of ruby-throated hummingbirds are black but appear shimmery red because of their microscopic structure.

Cheri Fussell, who lives in Greenwell Springs, was getting a kick out of seeing so many hummingbirds up close and learning facts about them. Though a first-time festivalgoer Saturday, she’s a longtime hummingbird enthusiast.

When Fussell lived in Zachary in the 1980s, she went through 10 pounds of sugar every week making sugar water for her feeders.

“I could get them to land on my finger,” she said. “They’re awesome. I just love them, just watching them, seeing the babies.”

Other festivalgoers checked out native plants for sale that attract hummingbirds. The St. Francisville area is a nice resting spot as the birds travel from North America to Central America, Henry said, with plenty of shelter and food available in the woods.

Most of the hummingbirds weighed in at about 5 grams, but they seemed weightless in the hands of spectators who helped release them.

They buzzed away “quick as a flick,” said 6-year-old Cora McPherson.

She was at the festival with her grandparents, who keep a few feeders outside their home in Denham Springs. They sometimes draw 20 to 30 hummingbirds at a time, Cora’s grandmother, Melinda McPherson, said.

“It’s amazing that they migrate so far,” she said. “We help them on their way.”