Black Tern, adult moulting from summer into winter plumage. Mays Point, Seneca Falls, New York State, USA.
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/59323989@N00">Tim Lenz</a> from Ithaca
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/seabamirum/2731684083/">Black Tern</a>