Herring Gulls diving - Ouse Estuary Nature Reserve - 15.1.2016

This group of Herring Gulls were taking off from the surface of the water, flying no more than a couple of metres up into the air and then diving into the water. The water is comparatively shallow. During the summer months the ground is usually baked dry. So it is unlikely that there are any fish in there. Although it is close to the tidal Mill Creek, I am fairly sure that the water is run-off from the hills across the road. This is not behaviour that I have seen before even in the sea or nearby harbour, with its fishing boats.