John:
I have seen this with loons a number of times, and it is amazing what they can eventually swallow. I always wonder how they handle the spiny fins, even if they can get it down. Most have some incredible digestive enzymes, and a really tough digestive tract.
The crop has had an impact on the image quality. Do like the chick following along. I might soften the reflection slightly at the bottom of the frame.
A classic example of 'biting off more than you can chew"