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Geese on roofs, really: Tracking geese around Chicago

Canada geese are learning Chicago hotspots.

As in resident geese figuring out black roofs are warmer in Chicago winters.

On July 10, while I fished with Dan Bernstein, he spotted a neck-collared Canada goose (black C136 on white collar) on the east side of Burnham Harbor.

A Canada goose with a neck collar (C136), part of a big Chicago study, spotted on the east side of Burnham Harbor. Credit: Dale Bowman

A Canada goose with a neck collar (C136), part of a big Chicago study, spotted on the east side of Burnham Harbor.
Credit: Dale Bowman

Randy Smith, wetland wildlife program manager for the Illinois Department of Natural Resources, directed me to report the band to reportband.gov. He said it was probably part of a study of resident Canada geese around Chicago.

That led to Brett Dorak, a graduate research assistant with the Illinois Natural History Survey. He has banded more than 800 Canada geese for the project, Ecology of Wintering Canada Geese in the Greater Chicago Metropolitan Area.

A couple hundred of the white collars have a letter with three numbers, but most are a letter and two numbers.

He emailed, “That particular bird is a male and was banded at the Museum of Science and Industry last summer during their molting period when they are rendered flightless.’’

During the molt in late June or early July, geese are flightless and able to be corralled inside an enclosure for banding. Last summer, 459 were banded, another 116 were banded over the winter and another 231 this summer.

“It is like a cattle roundup but with geese in the parks,’’ Dorak said.

Common sites have been around the Museum of Science and Industry and Marquette Park.

Leg bands are put on the right foot because that is the easiest for him to band with the way he holds the birds.

When the birds are banded, they are measured. The largest goose they measured so far was “just over 15 pounds, which for a wild goose is an extremely large goose.’’ Larger birds are Giant Canada geese, generally residents; while the smaller birds are the migrators from Canada, a subspecies known as interiors.

The neck collars are flexible enough to easily snap round the goose’s neck with an inch of overlap, which is epoxied.

One of the oddities he found during his work is a sighting of an orange-collared goose, which had been banded in 1999 as an adult in Ontario.

Another interesting thing he has found in banding is that the “urban areas is dominated by Giants; the interiors are more in the rural areas.’’

“For resident birds, I was quite surprised at the numbers and you look at migrators that stop over,’’ Dorak said. “That leaves a lot of birds in the Chicago area in winter time.’’

I would us resident humans are not surprised at that observation.

Dorak said he has “always been a waterfowl hunter and enthusiast from his days growing up northwest of Green Bay in Wisconsin. He worked for Ducks Unlimited in Montana.

“[Giant Canada] geese are a modern conservation story,’’ Dorak said.

In the 1950s, they were considered extinct, then a flock of Giants was found around Rochester, Minn. in 1962. Now the Mississippi Flyway has some 1.6 million Canada geese in it, which Dorak noted “is a pretty big number from being extinct.’’

“I have talked with dad and grandpa and it used to be if you shot a goose in the field, it was a good day,’’ Dorak, 29, said. “Now they are almost running over everywhere.’’

Back to modern days and transmitters.

Nine collared geese have been fitted with a transmitter, a small box with a solar panel, on the collar. These transmitters use cellular towers rather than old satellite technology.

“We started getting GPS points from roof tops and we were able to get permission to get up there,’’ Dorak said.

They would find as many as 350-375 geese on each black roof.

“It is a pretty unique sight of 350 of them sleeping tucked up on a roof,’’ Dorak said. “The adjacent roofs tops are white and gray and they spend no time on them. It seems to be a cold weather behavior.’’

He said they compared data with National Weather Service data and found those roofs were roughly 20 degrees warmer.

“They are definitely a clever, clever bird,’’ Dorak said. “Sometimes I think myself and others do not give them credit for their intelligence.’’

My report was one of about two dozen so far, Dorak said. Collars and bands have been reported from Ontario, southeast Wisconsin and northeast Illinois. Dorak would like to see more. Report bands at reportband.gov.