Following on from my previous image - once the gulls have filled their beaks with water they will throw their heads back and swallow. As you can see there is quite a lot of water that falls out of their beaks before they swallow!
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/43145783@N00">John Haslam</a> from Dornoch, Scotland
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/43145783@N00/943252687/">And now we swallow!</a>