Cornell Lab of Ornithology:
“Raptors—especially Cooper’s Hawks and Sharp-shinned Hawks—have become a familiar presence at urban and suburban feeders around North America. But it wasn’t always this way.
In a 2017 retrospective of Project FeederWatch results, we noted that Cooper’s Hawks increased their presence fourfold at FeederWatch sites over the past two decades. The agile accipiters occurred at just 6% of feeders in 1989, but by 2016 had increased to around 25% of feeders. Cooper’s Hawks have historically been thought of as a rural species, picking songbirds from branches in surprise attacks in the woodlands and forests. But one clear factor in the surge of FeederWatch reports has been their expansion into suburban and urban areas.
Scientists from the University of Wisconsin-Madison and the Cornell Lab of Ornithology took these results and went further, trying to find out what might be behind these increases. ”
