Yes, they can eat them”
It was not specified whether a seagull could eat the whole thing but they definitley do consume them one way or another. I guess that it depends on the acidity level of the hydrochloric acid in the stomach. I would find it hard to believe a bird like a seagull prying open a shell so I would conclude that the bird would eat the whole thing, and the shell would pass through the diestive track harmlessly. Aquatic birds probably go for the smaller clams if they didn’t want to drop it them, then poop out the shell later. By droping the clam, it would have to gain a lot of speed for the shell to crack on an adult clam, but I would guess that an aquatic bird would be able to eat the baby clam, but if the acids can’t penetrate the shell then the bird wouldn’t get any meat so I would guess that seagulls would most commonly go for the adults, because they would have more meat and would be more filling and nutritous.
