My friend Mike caught this Northern Pike and when he cleaned it he found this baby duck in its stomach. A duckling is nothing. We have caught Northern Pike with Muskrat tails hanging out their mouths.
They will eat anything swimming across the water such as snakes, mice, ducks, baby beavers, muskrat and any other critter they can fit in their mouths. Back in 1989 I was working for a fly-in lodge in Northwestern Ontario and we saw a 15-pound Northern Pike torpedo itself into shore where it slid up sideways on a smooth rock and took a baby seagull. If I caught that on video I'd be rich. It was a spectacular thing to see and just one of the many spectacles of nature I have seen while working in Ontario's far north.
Back in 1996 I was Walleye fishing off the dam in Bobcaygeon, Ontario when we observed a huge Musky come out of the deep current. He swam around in 4-foot water over smooth rocks looking like he was just enjoying the sun. Then faster than you could move your neck or eyes he bulleted into the shallows and hammered this duck. He shook his head like an alligator a few times and then slowly turned around and swam back into the deep current. It was just the coolest thing to see.