What makes a gull a gull?
Seagulls can be quite tricky to tell apart. Although we have 11 different species of gull that live in the UK, they all have a similar body shape and markings. These markings can change with the season and also vary with the age of the bird making it difficult to tell a herring gull from a common gull, although species can be determined by those with a well-trained eye. The length of a gull's body is highly variable depending on the species, and little gulls (the world's smallest gull) usually measure up to 30 centimetres, whereas great black-backed gulls can be a staggering 75 centimetres long. The wings of gulls are long and narrow when in flight and all species have strong webbed feet to help them to grip rocks and swim on the water's surface. Although mostly white with grey, black or brown markings, gulls can have colourful bills and legs, and these features can often be used to help identify them.
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Here's a guide to the gulls of the UK and colour ID guides to help you tell them apart:
The common name of the black-headed gull is misleading as an adult black-headed gull actually has a chocolate-brown head - and only in summer. In winter, the brown hood retreats and the birds have a largely white head with a dark spot behind the eye.
This relatively small gull is widespread in Britain and particularly common at inland sites in north England, Scotland and Wales, therefore it is not really a true ‘sea’ gull at all. Black-headed gulls are known to be fairly long-lived, with the oldest recorded individuals reaching ages of up to 32-years-old.
Resident in the UK all year round, the black-headed gull is a sociable bird that is often found in groups and has large colonies along the south and east coasts of England. In these colonies, pairs avidly defend their small territories from other birds using unusual ritualised displays.
The black-legged kittiwake is a small, graceful, cliff-nesting gull, named for its loud, nasal ‘kitti-wake’ call. As its common name gives away, its legs are usually black. However, a few individuals may have orange or reddish legs.
This seagull is a true ‘sea’ gull as it is only found around the UK’s coast and not inland. It can be found nesting on cliffs in the spring and summer (February - August) and spends the winter in the Atlantic Ocean.
The tips of the wings are black, giving the appearance of having been dipped in ink, and the tail is slightly forked. Outside of the breeding season, the adult black-legged kittiwake has darker grey marks around the crown and the back of the neck, and a dark mark behind the eye. The scientific name of the black-legged kittiwake - tridactyla - means 'three-toed', as the fourth toe of each foot has reduced over time to a mere stump, meaning it only has three functional toes instead of the usual four seen in other gull species.
The common gull, also known as the mew gull, is actually not all that common even though it can be locally abundant in some areas. It is generally similar in appearance to the herring gull but is smaller and has a more delicate appearance.
This gull is generally found throughout the UK all year round, but is more often found in more northern areas in summer and more southern areas in winter. There are four subspecies of common gull which occupy different ranges throughout the Northern Hemisphere including Russia and North America.
The common gull’s white head develops grey streaks in winter, when it can be seen on more inland areas such as farmland, lakes, playing fields and rubbish tips.
The glaucous gull is a winter visitor to the UK - mostly seen between November and March. It is not a common bird but can occasionally be seen around the coast or with large groups of other seagulls in inland areas, such as at rubbish tips.
It has mottled brown markings on its head when in winter plumage - which is when it can be seen in the UK.
This large pale gull is bigger and bulkier than a herring gull. It is also very similar to the Iceland gull, but it is significantly larger.
Great black-backed gull
The great black-backed gull is the largest gull species in the world, with a wingspan of up to 160 centimetres and weight of up to 2 kilograms. Its wings are blacker than the smaller lesser black-backed gull and the herring gull and it has a heavier build than both of these other species.
During the breeding season in the summer it can most often be found all round the UK coast, while in winter it is more often found inland.
Young great black-backed gulls undergo several plumage changes before taking on that of the breeding adult. Juveniles are pale brown with heavy white mottling, while immature birds are also mottled, but have a whitish head and breast, with a dark-tipped, pale bill.
A voracious predator, the great black-backed gull has been known to hunt puffins and grebes and regularly bullies other birds to steal their food. This species has been described as a 'merciless tyrant' when it comes to food!
Probably the most familiar gull on this page, the herring gull is found in high densities at UK seaside towns during the summer months, where it can be seen as a pest due to its highly opportunistic nature exploiting almost any available food source. During winter months this gull spends its time inland, often foraging around rubbish tips or reservoirs.
Herring gulls are able to excrete the salt from seawater through special glands above their eyes, helping them when they accidentally ingest seawater along with their food or have to drink saltwater when there is no freshwater available. The secreted salt then passes through the nostrils and drips from the end of their bill. A very long-lived species, herring gulls have been recorded at up to 32 years old.
The Iceland gull is quite rare in the UK, with only a small number of birds visiting during the winter months when it has mottled brown markings on its head.
This gull is smaller than both the gulls to which it is most similar – the glaucous gull and the herring gull. There are two subspecies of Iceland gull, one of which is found in Canada and another which overwinters in Europe, but breeds in Greenland. A relatively short-lived species, Iceland gulls only live for a maximum of four years.
Iceland gulls are usually seen on their own rather than in groups and stay near to their feeding grounds – either near to the coast or inland at reservoirs or rubbish tips with other species of gull.
Lesser black-backed gull
A middle-of-the-road species in relation to its size and weight, the lesser black-backed gull is widespread in the UK, and becoming increasingly common in urban areas. However, the species is at risk as more than half of the UK population is found at fewer than ten sites, and is therefore vulnerable to local extinctions due to extreme weather or conversion.
Found in the UK all year round, this gull breeds on the coast of Scotland in the summer and moves south and inland during the winter months.
There are several subspecies of the lesser black-backed gull which differ in the colouration of their back, with some being much darker than others. The subspecies that breeds in the UK can be differentiated from others due to it having the lightest coloured wings.
During the breeding season, individuals who are not partaking will form groups closeby to the breeders and spend the time relaxing as if on holiday. Lesser black-backed gulls are monogamous, forming breeding pairs that are retained for life. To attract a female, males call, perform courtship displays and may occasionally regurgitate food, all in the hope of securing a lifelong mate.
The little gull has an entirely black head in the summer breeding season, which becomes completely white during the winter aside from a dark cap and spot behind the eye. Aptly named, this species is the smallest gull in the world, with a wingspan measuring a maximum of 78 centimetres and weighing up to a diminutive 162 grams.
The wings are rounded and in adults, the underneath of the wings are darker than the tops. Young birds have a very distinctive bold, black zig-zag pattern on their back and wings and they don’t gain their full adult plumage until their third year.
The little gull does not breed in the UK, but it can be found around the coast between July and April. This species is known to mostly breed in northern Scandinavia, the Baltic republics and western Russia.
The Mediterranean gull is a particularly attractive bird with a blood-red beak and black head during the summer breeding season.
It was once rare in the UK, but can now be found along the coast in the south and east of the UK, where it can often be found with black-headed gulls. In winter Mediterranean gulls can be found further along the south coast in Cornwall and further north along the east coast, where they can be found in large numbers on some beaches in Norfolk and Kent.
It is thought that the warming climate of the UK may have made it more suitable for this species, explaining increased numbers in the area.
It can be found in southern and eastern Britain, often with lesser black-backed gulls. The lesser black-backed gull is similar in appearance, but the yellow-legged gull has a paler back and wings than the lesser black-backed gull. This species also has a very distinctive bright red ring around its eye.
The yellow-legged gull is found in Britain throughout the year, but in greater numbers in late summer and autumn when adults and juveniles disperse after breeding.