Smaller gulls
Handily, there are five regular species of smaller gull in the UK. Surprisingly, perhaps, Kittiwakes, the true ‘sea gulls’, are our most numerous breeding gulls. Common Gulls breed mainly in Scotland and are more widespread in winter. Blackheaded Gulls are ubiquitous, and Mediterranean Gulls are increasing exponentially as British breeders; while Little Gulls are largely seen on passage.
Size and head colour
Size almost goes without saying, but remember that Little Gulls are the smallest of all gulls, looking at times more like rounded-winged marsh terns. Kittiwakes are surprisingly small (though not in the Little league). Three of our smaller gulls are ‘hooded’ (Black-headed, Mediterranean and Little) in breeding plumage (though they only have remnant head spots when out of the breeding season). Note the hood colour (Black-headed Gulls have brown hoods, not black), and also note that Mediterranean Gulls have ‘fuller’ hoods than Black-headed Gulls.
Wing pattern
Of the hooded gulls, fully adult Mediterranean and Little Gulls have just about no white in the upper wing. Little Gulls have dark underwings (with a neat white trailing edge), Med Gulls have a white underwing. Black-headed Gulls have some black in the upper wing and dark wedges, etc., on the underwing. Wing-tip pattern is useful in distinguishing adult Common Gull and Kittiwake at a glance.
Soft part colour.
Note the colour of the bill and legs and feet. These can be surprisingly useful. Kittiwakes have black legs and feet.