Oscar writes: On the day I took this, most of the water on my local nature reserve was frozen, forcing the majority of the ducks to congregate on the small areas of open water remaining. The coots, one of the most territorial of the birds there, kept getting into scraps with each other but they never lasted very long. These two were fighting for quite a while, and I managed to get this image of them with both their legs up in the air! Occasionally their fights lead to injury, or even death, but fortunately for these two they backed down after a couple of minutes.
Nikon D800, Nikon 600mm f/4 AF-S II lens | Nikon 1.4x TC