Hello all, Last week as we're counting Yelkouan shearwaters in the Bosphorus (Turkey) my colleague noticed a bird that has unusual moult. It was very difficult to see it properly as the visibility was very bad and they were flying very fast but I can say that its size, silhouette and flight was exactly the same in comparison to other individuals in the flock. And it has very wide white patches on its neck and upper wing. We concluded that this bird has unusual moult.
As far as I know these abnormalities are much frequently observed in Cory's shearwater but I couldn't find any paper on puffinus shearwaters. Is there anyone who experienced such abnormality in puffinus genus? I wonder how frequent it is.