Mew Gull (Goéland cendré | Larus canus): Before I continue posting a few more of the bird photos I took in Kaua’i over the holidays, I thought I would post something I took last weekend right here in Vancouver. Aside from the fact that I like this photo, I would also like to test the collective wisdom of my followers to answer the following question: Why do Mew Gulls (like the one pictured here) dunk their bills repeatedly in the water when they are flying? Since they to do not seem to be taking a drink or catching any fish/crustaceans/seaweed (or anything else, for that matter), I was not sure why this was happening.
Since I took this picture, however, I have received several suggestions on various explanations on a number of Facebook groups. The two most compelling reasons I have heard are that it is doing this to attract fish to the surface of the water or (my favoured explanation) it does this to clean its bill of food and other debris, including fish scales and the like.
Taken January 9, 2016 from Jericho Pier, at the eastern end of Locarno Beach in Vancouver (British Columbia), Canada with a handheld Nikon D5200 and AF-S NIKKOR 200-500mm f/5.6E ED VR (ISO 400 | 500mm | f/5.6 | 1/1600). Cropped. Not baited, called in or set up.