Breeding plumage in winter

Black headed gulls are well known as non conformists when it comes to the timing of plumage change. Those hardy birding souls who have in the past endured the harsh winter weather to view the Llandegfedd Reservoir gull roost will have noted the change in black headed gull plumage from late January onwards. This bird at Riverfront Newport last week (mid December) was certainly the most advanced in the development of its summer head plumage I've seen.