Steve Spitzer was walking on Loyola Park Beach when he saw something in Lake Michigan. Close inspection revealed it was a Great Horned Owl pulling itself through the water with its wings. Luckily for the web, Spitzer caught the unusual behavior on camera.
"When I saw the video, I was surprised," says Jeremiah Trimble, Harvard's Collection Manager for the Ornithology Department. "I've seen Bald Eagles do that before, but that makes sense because they're hunting for fish. It's certainly not something an owl would choose to do."
Spitzer believes the owl was forced to the water to escape a pair of falcons. Falcons are very territorial, so it's possible they didn't want to share their space with a Great Horned Owl. He added that he came to the scene late, and that others said the owl was originally flushed out of the tree by crows before the falcons started going after the owl.
Matthew Zwiernik, an ornithologist from Michigan State University, says he's seen an owl do this once before. "It's not very common because they have no means of defense once they're in the water." An owl's talons don't make for good propulsion, so once they're in the water, they can't get out until they reach shore.
Zwiernik thinks the owl may have been trying to take over the falcons' nest—a common strategy for Great Horned Owls, who do not build their own nests. The falcons were clearly not very happy and likely chased the owl away.
"Getting in the water was [the owl's] last ditch effort," adds Zwiernik. "He's got a good looking breast-stroke, that's for sure."
Spitzer says the owl did make it to shore. Once it landed, the falcons continued to swoop towards the owl, so Spitzer and others stood around the bird as he dried off. Soon after, it flew away.
The falcons may have been Evanston Falcons that nest a few miles north of the area, Spitzer says. Because of their nesting location, he doesn't believe the owl was invading the falcons' nest.
This story has been updated to reflect more details from Spitzer.