The Joy Of Gulls

Gulls are fascinating, frustrating and frequently baffling. When you first start looking at gulls in bird guides they're quite straightforward: they're all in pristine adult plumage with flat lighting and it's a doddle. Then you go out on a blustery Winter's day when the light's anything but flat and you're faced with a bewildering array of young plumages and changing tones of grey as birds fly around and you wonder what you're looking at. So you go online and soon you're even more overwhelmed by the wealth of detail involved in identification. And then you discover that as well as the variations with age, the subtle differences between some very closely-related species and subspecies, and the almost casual way that vagrant gulls may turn up anywhere, there's always the chance you're looking at a bird of mixed parentage. It can become intimidating, so many people get put off and give up, which is a shame.

I'm not in any way a gull expert — every year by Easter I've become confident that I can identify a yellow-legged or a Caspian gull 70% of the time when I see one and then come September I'm starting the learning curve all over again.— but I enjoy doing a bit of gull-watching. I thought it might be worth putting together some very general notes from my own experience for people like me who are baffled but still game. They probably won't be enough to clinch an ID but they may be enough to provide a starting point when you see something "not quite right."

• If you've found a gull that looks a bit unusual concentrate on making notes on what you're seeing rather than trying to make an ID.

• Some birds you're never going to identify. This is OK.

General identification tips

• At all ages concentrate on:
• The size, general impression and jizz of the bird
• Shape of head
• Shape and colour of bill
• Colour of legs and feet
• Colour of eye and eye ring
• In adults note:
• Colour of upperparts
• Colour of primary feathers
• Any mirrors on primaries
• In younger birds:
• The colour(s) of the back and wings
• Tail banding, if any

Some of these details are outside the scope of these notes, you'll be using them to confirm or deny a possible identification.

Benchmark species

These are the species that used to be "all the gulls of Britain" in the books when I first started birdwatching.

Little gull

• Tiny, delicate-looking and with a tern-like flight
• Immatures pale with a black W on their wing
• The contrast between the pale upperwing and black underwing of an adult is striking even at a distance

Black-headed gull

• Small, silvery gull, pointed wings have very prominent white leading edge and thin black trailing edge
• Thin, pointed bill
• Depending on the age, time of year and lighting the bill and legs can be anything between watery orange and dark crimson
• Breeding adult unmistakable with its brown hood

Black-headed gull, Pennington Flash

Common gull

• Medium-sized gull, dark grey back, wings slightly rounded at the tips, rounded head, pointed yellow bill, legs grey to yellow
• Adults in breeding plumage have an open facial expression and beady eyes 
• Adults in Winter often have a smudgy dark ring on the bill

Common gull, Stretford

Mediterranean gull

• General impression from a distance is of a ghostly pale common gull with a dark, blunted bill
• Breeding adult unmistakable in its black hood

Mediterranean gulls, Martin Mere

Kittiwake

• Medium-sized gull, dark grey back, more pigeon-like proportions than other gulls with quite a lot of chest, pointed yellow bill, legs black
• Immatures pale with a black W on their wing

Herring gull

• The archetypal big grey-backed gull
• Females tend to be slightly smaller and have more rounded heads than males
• Adult: pale eye (very rarely dark), silvery upperparts, yellow bill with striking red gonydal spot (where the bill bulges about two-thirds along the base) and pink legs (though some may have yellow legs)
• Scandinavian herring gulls are bigger and slightly darker

Lesser black-backed gull

• More elegant looking than herring gull, at all ages
• Immature plumages always darker and colder than herring gull

Iceland gull

• Smaller-headed and slightly more delicate looking than a herring gull
• Very pale with no black to the plumage

Great black-backed gull

• Huge
• Ponderous, powerful flight

Great black-backed gull, Leighton Moss

Glaucous gull

• A ghostly edition of a great black-backed gull with no black in the plumage
• Salmon-pink bill of immature birds very striking

Glaucous gull, Hollingworth Lake

Birds that used to be "herring gulls"

Yellow-legged gull

• Like a big, hefty herring gull with a long, blunt bill like an old fashioned butter knife
• Adult upperparts common gull grey, not much white in the primaries
• Immature plumage more like a paler, warmer version of lesser black-backed gull than darker version of herring gull

Caspian gull

• A big gull but elegantly-proportioned: as a lesser black-backed gull looks more elegant than a herring gull a Caspian gull looks more elegant than a lesser black-backed gull
• Long winged, rounded head, long neck, long legs, long bill
• Immature plumages seem to get a whiter head at a younger age than do herring gulls and yellow-legged gulls

Probable (possible?) Caspian gull, West Kirby
I puzzled over this for ages and I'm still not wholly convinced

American herring gull

• I've only seen these in the States; I'm not convinced I could tell an adult American herring from a Scandinavian European herring gull;  both are big and husky
• First Winter American herring gulls are peculiar: from a distance they're almost uniformly brown

Visitors

Bonaparte's gull

• Like a small edition of a black-headed gull with a small black bill and short bubblegum-pink or puce legs

Ring-billed gull

• Intermediate in size between common gull and herring gull
• Square-headed like a herring gull but wings like a common gull
• The black ring on the bill is more distinct than the smudgy effort on a Winter common gull

Laughing gull

• Everything about a laughing gull looks stretched out: a very long bill. a low flat head, long wings and a long rear end after the legs

Like I say, not expert notes but I hope they're helpful.