The black-headed gull (Larus ridibundus); Mr and Mrs, side by side, so that you can compare. There not much to distinguish them is there? The male, at the back, is slightly larger and has a slightly more stout bill. It also has a little more colouring on its face. These birds are in summer plumage and despite being named black headed gulls they are not gulls with black heads at all! The colouring is chocolate brown rather than black and it is their face, not their head, that is chocolate coloured. In the autumn they moult and lose that lovely dark head plumage and become white faced with just a dark comma shape behind the ear.
In Dorset this is one of our two most common species of gull, the other is the herring gull, and in winter the numbers are reinforced by incomers from further north. They nest on Brownsea Island and around Poole Harbour and at various other coastal locations where there are shingle banks or islands.
Spotting gulls is a tricky and getting the identification right can be really difficult for a number of reasons. Several have different plumage in winter than they do in summer. They also have differing habitats in winter moving from their breeding sites to anywhere there is easy food and they can be seen around the harbour in Swanage Bay and around Weymouth, especially Radipole Lake, where its is usual to see over 100 standing in puddles in the car park fully expecting all cars to deviate around them. The problem with black headed gulls is they gather together in quite large numbers and other, much rarer, gulls tend to move in with them. You have to virtually look at every individual in the crowd to see if there is a different species lodging there. Stand in the car park at Radipole and check the legs and beaks. If they are red then you have black headed gull; if it is not but the bird is the same sort of size, then you have some thing else that needs a closer look - common gull or mediterranean gull perhaps or even something much rarer. At least you can always pop in to the RSPB visitor centre and find out from them what it is you have seen.
Like the starling, the black headed gull is a bird with attitude. It is aggressive and noisy and its harsh call is like nothing else, just a rasping shriek.