I once saw a flying creature that appeared to be a pterodactylpterosaur (except for the size), ever since since i've been on the lookout for any kind of "bird" with a diamond/kite shape at the end of it's tail, as that is what i remember most distinctly.
I really appreciate the hint! I looked at some google-images of flying herons & cranes. I don't think it was one of those, but it was also some time ago (and old memories can get rewritten as you recall them).
I was not able to find a picture of a frigate bird that had a significant tail, so I don't think so. That was the most striking thing about it, I had never seen a bird with a long tail (like... about the same length as it's body).