My informant heard the following urban legend from her older sister, who lives in northern Virginia. She says that she doesn’t really believe it, but it could be true because of the chemical reactions involving alka seltzer.
“If you feed a seagull alka seltzer, the bird will explode within around half an hour because it cant expel the gas through farting or burping so the gas builds up inside it. My sister heard this from a friend in her rock-climbing group in Virginia, and he said he had tried the experiment with his brother or something.”
My informant is not sure if this is true, but says she thinks it seems plausible. She is skeptical, however, about whether or not her sister’s friend actually tried the experiment. I have also heard this urban legend, though I heard from my older cousin while feeding seagulls at a beach barbecue when I was around ten. There is a similar urban legend involving rice, which says that birds will die after eating rice because the grain expands in their stomach. I do not believe either of these are very plausible, but could not find any definitive information on either.