All species › To the gulls and terns › Comparing gulls

Comparing gulls

Gulls look alike, but a handful of features usually separates them: leg colour, the head, a red spot on the bill, black in the wing tip and the shade of grey on the mantle. Tap what you see below; the list then shows only the species that fit all your choices.

• Within one row you can pick several values (yellow or pink legs); across rows everything must match.
• Everything refers to adult birds. Immature gulls differ a lot and take up to four years to mature; see the species page for those.
• Leg and bill colour vary with season and light. If in doubt, pick two values.

Species	Length	Legs	Head, summer	Head, winter	Bill	Red on bill	Wing tip	Mantle	Eye	What to look for
Large gulls
Great Black-backed GullLarus marinus	71–79 cm	Pink	White head	White	Yellow	Red spot	Black	Black	pale eye, red ring	Very large gull with a black back, pink legs and a massive bill; the black wing tip merges with the back and has a large white mirror. Lesser Black-backed Gull is smaller, slate grey and yellow-legged.
Yellow-footed GullLarus livens	69 cm	Yellow	White head	White	Yellow	Red spot	Black	Dark grey	pale eye, yellow ring	Very large gull with a slate-grey to blackish back, bright yellow legs and a very heavy bill with a bulbous tip and red spot; the head stays white in winter. Western Gull has pink legs.
Glaucous GullLarus hyperboreus	68 cm	Pink	White head	Streaked	Yellow	Red spot	No black	Pale grey	pale eye, yellow ring	Very large pale grey gull with pure white primaries, pink legs and a heavy bill; flat head and short wing projection. Iceland Gull is slimmer, with a rounded head, a short bill and long wing tips.
American Herring GullLarus smithsonianus	56–66 cm	Pink	White head	Streaked	Yellow	Red spot	Black	Pale grey	pale eye, orange ring	Large gull with a pale grey back, pink legs, a pale eye and a yellow bill with a red spot; black wing tip with small mirrors. Vega Gull is darker grey; Ring-billed Gull is smaller and yellow-legged.
Western GullLarus occidentalis	56–66 cm	Pink	White head	White	Yellow	Red spot	Black	Dark grey	pale eye, yellow ring	Dark grey back with pink legs and a thick yellow bill with a bulbous tip; the head stays almost white in winter. Yellow-footed Gull has yellow legs; American Herring Gull has a paler back.
Slaty-backed GullLarus schistisagus vagrant	55–67 cm	Pink	White head	Streaked	Yellow	Red spot	Black	Dark grey	pale eye, red ring	Dark slate-grey back, bright pink legs and a pale eye; in flight a row of white spots between grey and black on the hand and a broad white trailing edge. Vega Gull is paler grey.
Vega GullLarus vegae vagrant	55–67 cm	Pink	White head	Streaked	Yellow	Red spot	Black	Medium grey	pale eye, red ring	Medium-grey back, pink legs and a red eye-ring around an iris that ranges from pale yellow to almost dark; heavily streaked collar in winter. American Herring Gull is paler grey; Slaty-backed Gull is darker.
Kelp GullLarus dominicanus vagrant	54–65 cm	Greenish-yellow	White head	White	Yellow	Red spot	Black	Black	dark eye, red ring	Black back with greenish-yellow legs and a white head that stays almost unstreaked in winter; wing tip almost all black, with one small mirror. Great Black-backed Gull has pink legs and a large mirror.
Lesser Black-backed GullLarus fuscus	52–64 cm	Yellow	White head	Streaked	Yellow	Red spot	Black	Dark grey	pale eye, red ring	Slate-grey back with bright yellow legs and long wing tips; the black tip merges into the back, giving little contrast. Great Black-backed Gull is larger and blacker, with pink legs.
Iceland GullLarus glaucoides	50–60 cm	Pink	White head	Streaked	Greenish-yellow	Red spot	Little black	Pale grey	pale eye, red ring	Pale grey gull with a rounded head, short bill and wing tips well beyond the tail; the tip ranges from pure white to grey or dark grey with mirrors. Glaucous Gull is bulkier and heavier-billed.
Glaucous-winged GullLarus glaucescens	50–59 cm	Pink	White head	Streaked	Yellow	Red spot	No black	Pale grey	dark eye, red ring	Large, heavy gull with a dark eye and wing tips the same grey as the back, marked with white spots; heavily smudged head in winter. Glaucous Gull has white wing tips and a pale eye.
California GullLarus californicus	47–54 cm	Greenish-yellow	White head	Streaked	Yellow, black band	Red spot	Black	Medium grey	dark eye, red ring	Medium-grey back, dark eye and greenish-yellow legs, with a yellow bill showing both a black band and a red spot. Ring-billed Gull is paler grey, with a pale eye and no red spot.
Medium gulls
Heermann's GullLarus heermanni	46–53 cm	Black/olive-grey	White head	Streaked	Red	Red bill	Black	Dark grey	dark eye, red ring	Dark slate grey on back, breast and belly, with a white head, black legs and a deep red bill with a black tip; black tail with a white terminal edge. In winter the head is streaked grey-brown.
Ring-billed GullLarus delawarensis	43–54 cm	Yellow	White head	Streaked	Yellow, black band	None	Black	Pale grey	pale eye, red ring	Pale grey back, pale eye with a red eye-ring and a yellow bill with a complete black band; yellow legs. Short-billed Gull has a dark eye and an unmarked bill; California Gull also shows a red spot.
Black-tailed GullLarus crassirostris vagrant	44–47 cm	Yellow	White head	Streaked	Yellow, black band	Red spot	Black	Dark grey	pale eye, red ring	Dark slate-grey back, yellow legs and a yellow bill with a black band and red tip; broad black band across the white tail. Lesser Black-backed Gull has a white tail and an unbanded bill.
Short-billed GullLarus brachyrhynchus	41–46 cm	Yellow	White head	Streaked	Greenish-yellow	None	Black	Medium grey	dark eye, red ring	Rounded head with a dark eye and a short, thin, unmarked bill; medium-grey back, large white mirrors and, in winter, a densely smudged head. Ring-billed Gull has a pale eye and a banded bill.
Common GullLarus canus vagrant	40–46 cm	Greenish-yellow	White head	Streaked	Greenish-yellow	None	Black	Medium grey	dark eye, red ring	Medium-grey back, dark eye and a thin greenish-yellow bill without a spot; two large white mirrors in the black wing tip. Short-billed Gull is very similar but has a shorter bill and a more densely smudged winter head.
Laughing GullLeucophaeus atricilla	39–46 cm	Black/olive-grey	Black hood	Mask	Red	Red bill	Black	Dark grey	dark eye, white eyelids	Hooded gull with a dark slate-grey back and a long, slightly drooping red bill; the black wing tip blends into the grey without a white band. Franklin's Gull is smaller, with a shorter bill.
Ivory GullPagophila eburnea vagrant	40–43 cm	Black/olive-grey	White head	White	Blue-grey	None	No black	White	dark eye, red ring	All-white adult with short black legs, a dark eye and a blue-grey bill with a yellow tip. Glaucous and Iceland Gulls are also pale but have a grey back and pink legs.
Black-headed GullChroicocephalus ridibundus	37–43 cm	Red	Brown hood	Ear spot	Red	Red bill	Little black	Pale grey	dark eye, white eyelids	Chocolate-brown hood ending at the rear of the head, dark red bill and legs; in flight a white leading edge above dark undersides to the primaries. Larger than Bonaparte's Gull, which has a black bill.
Black-legged KittiwakeRissa tridactyla	38–41 cm	Black/olive-grey	White head	Ear spot	Greenish-yellow	None	Black	Medium grey	dark eye, no conspicuous ring	Short-legged gull with black legs, an unmarked greenish-yellow bill and a clean black wing tip without a mirror. Red-legged Kittiwake has red legs, a darker back and a grey underwing.
Red-legged KittiwakeRissa brevirostris	35–39 cm	Red	White head	Ear spot	Yellow	None	Black	Dark grey	dark eye, no conspicuous ring	Small gull with coral-red legs, a short yellow bill and a large dark eye; dark slate-grey back and a grey underwing. Black-legged Kittiwake has black legs, a paler back and a white underwing.
Small gulls
Franklin's GullLeucophaeus pipixcan	32–36 cm	Red	Black hood	Mask	Red	Red bill	Black	Dark grey	dark eye, white eyelids	Small hooded gull with a dark slate-grey back, broad white eyelids and a white band between the grey and the black of the wing tip. Laughing Gull is larger, with a longer bill and no white band.
Sabine's GullXema sabini	34 cm	Black/olive-grey	Grey hood	Mask	Black	None	Black	Medium grey	dark eye, red ring	Three sharply defined areas on the upperwing (grey, black and white), a forked white tail and a black bill with a yellow tip; grey hood in breeding plumage. Black-legged Kittiwake lacks the white triangle.
Ross's GullRhodostethia rosea vagrant	29–31 cm	Red	White head	Ear spot	Black	None	No black	Pale grey	dark eye, red ring	Small gull with a wedge-shaped tail, a tiny black bill and red legs; in breeding plumage a thin black necklace and a pink flush. Little Gull has a square tail and a blacker underwing.
Little GullHydrocoloeus minutus	29–30 cm	Red	Black hood	Ear spot	Red	Red bill	No black	Pale grey	dark eye, no conspicuous ring	Very small gull with a black hood lacking white eyelids and a fine dark bill; rounded pale grey wings with no black tip and a sooty-black underwing with a white trailing edge.
Bonaparte's GullChroicocephalus philadelphia	28–30 cm	Red	Black hood	Ear spot	Black	None	Little black	Pale grey	dark eye, white eyelids	Small, slender hooded gull with a black hood and a thin black bill; long white wedge on the outer wing and a white, translucent underwing, where Black-headed Gull shows dark undersides to the primaries.

The features come from the species accounts in this guide, supplemented from standard field guides. Lengths are those on the species pages; the groups are a convenience, not a fixed classification.