If you stumble upon a swan that appears to be stuck on the ice, wait a minute before you go calling for help. It's probably just fine. 

According to the Minnesota Department of Natural Resources, it is perfectly safe for swans to swim in icy water. They probably aren't trapped or stuck, so they don't need to be rescued. This goes for other waterfowl as well. 

"People see them this time of year resting on frozen water or swimming about in small pockets of open water within ice," explains Erica Hoaglund, central region nongame wildlife specialist. "Observers assume they're trapped when most of the time they're not and move on in either a few days or a few weeks. It usually is not the emergency it can first appear to be."

The DNR explains that the birds can appear trapped because they—like humans—move around less when it's cold out. 

In the unfortunate and rare occasion that the bird is actually trapped or in distress, do not risk your own safety to rescue it. The DNR says the animal likely has an underlying illness or injury, and it might not even be possible to rehabilitate the animal after a rescue. 

While it might be sad, some animals will die over the winter and go on to provide food for other animals like mice and bald eagles.