Note: All banding, marking and sampling at the Cedar Grove Ornithological Research Station is conducted under a federal bird banding permit issued by the U.S. Geological Survey’s Bird Banding Lab.
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It’s a crisp, fall morning at the cabin-like Cedar Grove Ornithological Research Station. Banding Director Danny Erickson and his team are here to trap raptors.
Luckily for them, the skies are soaring with action.
“Usually it's not like this,” Erickson says. “It's a lot more long hours of waiting, punctuated by brief moments of excitement. But today is a good day.”
Erickson hides out in the station’s bird blind – it’s like a garden shed with a viewing slot of the horizon.
He lures raptors with a smaller, invasive bird, the European Starling. It’s tethered to a string, which he lifts up and down in the air so that it looks injured.
It’s like watching a puppet master at work.
“This is perfect ideal weather,” Erickson says. “That light northwest wind, sunny skies, it’s perfect for raptor banding.”
The lure works. Like an arrow, a Sharp-shinned hawk dives toward the starling – but before the hawk reaches its prey, it gets caught in the net trap.
“Go to [trap] two, five and six!” Erickson instructs.
Emma Fike, one of the station’s interns, bursts through the blinds’ doors to untie the hawk and bring it to the back of the station for banding.
Safely catching, tagging, measuring and releasing birds of prey, like hawks and owls, is all part of the work done each fall at the Cedar Grove Ornithological Research Station.
It’s in the ideal spot for fall migration.
“We're situated about 300 meters from Lake Michigan,” Erickson says. “So on a west wind day or a northwest wind day, the raptors get pushed against the lakeshore. They don't wanna fly over the open body of water, so they essentially hug the coastline. That allows us to see them in large numbers and try to trap and band them, as well as count how many are passing over [the station] and compare those numbers year to year.”
Listen to the full conversation with Cedar Grove Banding Director Danny Erickson, below.
Decades of raptor banding
This year marks Cedar Grove’s 76th year. Tucked away just outside Sheboygan, it’s the oldest, continuously operated raptor banding station in North America.
“We’ve got roots dating back to the 1920s and 1930s,” Erickson says. “It was started by the Milwaukee Public Museum to document raptor migration in the area and study bird migration along Lake Michigan. Their scientific efforts stopped when World War II started, so the station kind of lay unoccupied for several years.”
Things started looking up for the station in 1950, when two Milwaukeeans fresh out of high school – Daniel Berger and Helmut Mueller – learned about it and took over its operation.
Erickson says Berger and Mueller were pioneers in raptor banding research:
“Falconry has a rich history in the world, especially in Asia, so they used a lot of falconry techniques and brought them back,” he says. “The Bal-chatri trap, for example, is a type of trap they used, along with certain netting techniques and the use of lures to really help bring the raptors down. This has been a common technique used at other banding stations in North America.”
Berger and Mueller’s data also helped track the massive decline in raptor populations in the mid-twentieth century, during the era of DDT. The pesticide caused birds to lay thin-shelled eggs.
“So by studying these raptors we were able to see that there was this decline, and enact legislation that effectively banned DDT [in 1972],” Erickson says. “Then we saw a subsequent increase in raptor populations. So birds, not just raptors, act as barometers for environmental change – and with healthy bird and raptor populations, that equates to human health and well-being as well.”
Erickson says he feels honored to carry on the work at the station.
“One of the joys of [working at the station] is being able to share this with people and see it through fresh eyes,” he says. “ It’s a hidden gem, and I’m excited to showcase it.”
The research station sits on land managed by the Wisconsin Department of Natural Resources and was designated a State Natural Area in 1952.
The nonprofit operates independently of the state and has a crew made up of Erickson, two seasonal interns and a rotating team of volunteers. Its work is supported by donations, and an endowment with the Natural Resources Foundation of Wisconsin.
Every fall, from mid-August to mid-November, the station runs like clockwork, nearly 24/7. From dawn to dusk, the seasonal crew trap, band, measure and release diurnal raptors. And then from dusk to dawn, they keep an ear out for owls.
It starts all over again the next day.
“We're approaching 50,000 raptors banded [since 1950], and I have to find out when we reach that milestone, but it's within the next, if not this year, maybe next year,” Erickson says.
Raptor banding
Back inside the research station, I follow the sounds of the Sharp-shinned hawk Erickson’s team just caught.
Aubrey Schwonek, a seasonal intern from Sheboygan Falls, places the hawk's head inside a container the size of a Pringles can.
The darkness inside the can calms the bird down and gives Schwonek easy access to its feet.
She then clamps a small bracelet with a unique ID number to the bird's ankle.
“We want to make sure that the band fits,” Schwonek says. “That it’s snug, but it's not abrading the leg at all, and that it's not too big to fall off the foot. We want to find that good in-between.”
She then records measurements and observations about the hawk, like its wing length and plumage.
“Next I'm gonna look at the bird's wing pit, which is under their wing and above their leg,” Schwonek says. “This is where they store a lot of fat; and on a scale of 0 to 5, I would score this bird a 2. So he has some fat, but not a ton, but he's doing pretty good. That's a pretty average number for what we're seeing.”
The information she gathers today will be sent to the U.S. Geological Survey.
So if this bird is caught again, its ID number will connect it to all the other data the scientists are gathering on it. It’ll help them study the bird population’s migration pattern, its survival rate and whether it's breeding.
This entire process takes less than 10 minutes… and then it’s time to let the bird fly free.
UW-Green Bay graduate student volunteer Gweni Malokofsky takes on the role of releasing raptors today. She holds the Sharp-shinned hawk securely with her right hand.
“I'm gonna hold the bird in my hand and orient him towards the open space away from the net so he doesn't get caught for a second time today,” Malokofsky says. “And then I'm going to gently let him go, and he's gonna fly off.”
The hawk flaps its wings and flies toward the tallest tree to perch.
“Perfect,” Malokofsky says, admiring the hawk.
As the day winds down, so does the number of raptors flying into traps.
Cedar Grove trapped 52 raptors in total by the end of the day, and counted over 600 – one of their busiest days of the season by far.
Erickson and the station’s interns will soon take down the nets, eat dinner and get ready for a night of owl banding.
As I pack up to leave, I ask Erickson what he hopes for the future of the station.
“I hope we're around for another 70 years and to keep going for as long as there's raptor migration,” He says. “I think one of the best things that we can do as a station is to bring on the younger crowd, help develop the young professionals and to expand our presence into the community as well – share the joy of raptor migration with other people. I really think that's something I really want to build towards.”
I hope so too – visiting the station is an experience I’ll never forget, and one I hope more Wisconsinites learn about.
You can support and visit the Cedar Grove Ornithological Research Station by signing up for a field trip to the station through the Natural Resources Foundation of Wisconsin.
