CHICAGO (CBS) — This season’s annual Audubon Christmas Bird Count, which continues through Monday, already has produced some interesting numbers.

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The man who organizes the bird counts in the Chicago area is Joel Greenberg, and he called the number of Sandhill crane sightings on a count a few days ago “extraordinary.”

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“On that particular count, the previous high was six, and this year there were 900 of them,” Greenberg said. “By middle to end of December in northern Illinois, they’re usually gone. So to get big flights this late is unusual. If it was in March or October or November, it wouldn’t have been; but being late December, it’s unusual.”

On Thursday, Greenberg was watching a bald eagle in Lake County, and his group of birders spotted three of them. That was a little unusual, because — as with the cranes — it’s late in the season.

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“To see three in a day is pretty cool,” he said. “It adds a lot of joy and is a clear manifestation of a species coming back after being severely depleted.”