It's bad luck to kill a seabird! Love the flavor of this, seems like something that GMs can easily introduce and looks like it would be really fun to slot into an ongoing campaign.
Edit: forgot to mention my one piece of constructive criticism--in the printer friendly version, the white text with the gray drop shadow on the white and gray background is a bit hard to read. Maybe gray text with a black shadow or just black text would be easier, I don't know.