It's a good thing that a group of ice fishermen in Pennsylvania had a camera with them Monday. Otherwise, few would have believed their story.

The friends had set a line on a frozen lake about two hours north of Pittsburgh. When they pulled it up, they were surprised to find a live bird, flapping vigorously.

"Blew my mind, I couldn't believe what I saw!" Nicholas Colangelo wrote on YouTube, where he posted the video of his friend Fred Christensen.

The video shows Christensen untangling the bird and releasing it. The animal scoots across the ice toward a small patch of open water and a flock of other ducks. (See a colossal catfish catch.)

The bird is an adult male red-breasted merganser, says Geoff LeBaron, an ornithologist who serves as the director of the Audubon Christmas Bird Count.

"I have not heard of this happening before but it isn't totally unsurprising, especially in a winter like this," he says.

That's because mergansers are fish-eating ducks that often hunt under ice, where they can stay submerged for up to about five minutes. The ducks are common in the Northeast, although many of those that have been wintering on inland bodies of water have been struggling this year, with high ice cover restricting their movement and access to prey.

Many of the birds have been food deprived, making them more likely to go after the easy prey of fish on hooks.

"The good news here is that the bird wasn't drowned, which could easily happen, and it didn't swallow the hook, which makes it hard to save," says LeBaron.

It's hard to say if the merganser in the video will make it through the winter. "If he was totally healthy he would have flown right away," LeBaron says. "I think he skittered off because he was exhausted and probably a bit food stressed."

With warmer weather expected soon, times should get easier for waterfowl.