The Delaware Nature Society has launched a new bird banding program to track birds in the Ashland Nature Center and at the Bucktoe Creek Preserve in Pennsylvania.
Members of the public are allowed to observe the program at work, so Delaware Public Media’s science reporter Eli Chen went to see how bird banding works in person.
It’s a bright, humid morning at the Ashland Nature Center and I’m walking on a forested trail with Ian Stewart, an ornithologist at the University of Delaware. We’re heading toward thin, black nets set up like a volleyball court, except they’re actually set up to catch birds.
“Just very thin nylon and you see there’s a little pocket here, it hits the net and sits in this little pocket here. As you can see, there’s vegetation on both sides and it’s in the shade, so the birds can’t see the nets,” said Stewart.
On a good day, Stewart will catch around 20 birds. That morning, I watched a few catbirds, robins, and a cardinal land in the nets -- as well as a fledgling chickadee Stewart untangled.
“What you have to do is very gently pull away from the net, open their feet and eventually, they’ll let go,” Stewart explained.
When he’s done with the chickadee, Stewart moves on to a young catbird, and notices he’s being watched.
“See, here’s an adult coming to check it out.”
When all the birds are bagged, a volunteer holds them and we walk back to a folding table that’s covered with papers and equipment.
“When we catch them, we do all sorts of measurings,” said Stewart.
First, he weighs them, then takes the bird out of the bag to make body measurements and determine its sex.
“You see how the feathers are missing in the middle of the body? So females lose their feathers on their breast so they can incubate the body better.”
He takes out a bunch of small, shiny metal bands, hanging from a loop of wire. He takes out one, which is inscribed with its own unique number.
“Different birds, depending on how big they are, get different bands,” Stewart said.
This whole time, he’s also scribbling data on a spreadsheet that will be sent to the U.S. Geological Survey. Because each bird is wearing a unique band, you can learn a lot about a bird’s migration routes and population levels. If they’re flying earlier or later to a region, it’s possible they could be responding to changing climates.
After the bird is accounted for, it’s time to set it free. Stewart hands me a catbird, which dives immediately into the ground.
“That’s okay, the catbird is a bird that usually stays low, so when you let them go, their response is to dive down into the vegetation to recover and fly away," said Stewart. "So it’ll be fine.”
Stewart’s data will also be used to create a bird banding position at the Delaware Nature Society. But before anyone can think about applying, becoming a licensed bird bander can take a bit of time -- four years, that is. In the meantime, if you want to see how ornithology is done, the public is welcome to watch Dr. Stewart at work until the end of September.