Birds eat fish. Now, there is documentation that fish, codfish at least, eat birds.
Fishermen working out of Dutch Harbor in Alaska in 2011 found the remains of 74 birds in the stomaches of codfish being processed. The remains were sent to the University of Alaska, Fairbanks.
Sea birds were the meals of choice — Crested Auklets and Thick-billed Murres, for two example. Scientists say this is something about which they know little. Bird remains previously have been found inside fish, but the significance of the 74 birds found at Dutch Harbor is unknown.
Previous instances of cod eating birds were called rare in the news story discussing this.
This does not appear to be an issue here. Asked about it, Carrol Henderson, supervisor of the non-game wildlife section of the DNR, said, “I'm sure that larger bass, northerns, and muskies are fully capable of taking young loons, ducks, Canada geese, trumpeter swans, and grebes. But I am not aware of any summaries of such behavior.
“Observations would be incidental at and sporadic at best,” he said.
Turtles can be a problem. Henderson recalled that when the Wisconsin DNR was involved with early stages of trumpeter swan restoration, snapping turtles were removed from some of the release sites because the snappers were taking cygnets.
That has to be a big turtle.
Below is an auklet. Crested Auklets are about the size of pigeons. I've eaten one. They taste a bit fishy.