Laridae

Holarctic Gulls 

The gulls from  a group of about 50 species of which over two third of them in the holarctic region, i.e. roughly the whole northern hemisphere. Nevertheless a number of the species mentioned here migrate or wander south of the Equator. Most of them are coastal birds, but there are also more inland species. They vary much in size and coloration, but most gulls have white bodies and silvery or bluish gray to black upperparts and black and white markings at the tip of the wing. On the other hand, there are entirely white gulls and gulls with very dark plumages. Bills are also very variable  in color: black, red, yellow, with or without red dots on the gonys or black markings at the tip. The shape and proportion of the bill may vary also. Summer and winter plumages may differ considerably. Quite a number of species resemble each other a lot and differences are subtle. This may cause difficulties with the identification in the field if not seen properly, but even dead or in the hand it may be difficult for the inexperienced 'gull-watcher'.  Juvenile gulls need two to four years to reach their adult plumages and often start with a brown mottled plumage and a dark bill  which gradually change until maturity. 

Gulls are constantly under taxonomic review and many former subspecies are considered to be true species or have been transferred to another taxon or have been rejected. Especially the large group of the closely related species and subspecies of argentatus, vegae,  heuglini, armenicus, michaellis, cachinnans, fuscus, glaucoides and thayeri is still subject of taxonomic discussion. All of them more or less similar sized with from almost white to black backs and flesh to yellow-colored legs, but - based on advancing insights - with much less intergradation and hybridization as was supposed until recently. But they sometimes do. This group is of a great taxonomic complexity  but the discussion about the the (sub-) specific relations makes progress.

Even some generic names are subject to discussion. The majority of the gulls are placed in the genus Larus. Some authors consider Rissa  to be also Larus.  The list below might become (or is already) in need of an update.

Identification of gull skulls can be very tricky, because in  many species they are very much alike. Especially those of the similar sized  and closely related species. Individual variation in size and the difference between the sexes may be considerable. Males tend to be larger and more robust than females. And to make things even more complicated: a large individual  of a smaller species may be larger than a small individual of a larger species. Many gulls travel over long distances from their summer grounds to their wintering area. Sometimes they even cross oceans by following ships or during strong winds and storms. Therefore individuals of most species and subspecies can be found far from their normal distribution.  In many cases it is not possible to identify a dead gull with certainty only by its  skull. Other characteristics such as plumage colors and patterns and bill colors are important for correct identification.

Since bill colors tend to fade after preparing the pictures are not fully reliable in this respect.

Medium to large gulls

Genus Larus

• Herring gull Larus argentatus, two subspecies:

•    Scandinavian Herring Gull L. a. argentatus, Scandinavia, Finland, south-east Baltic to White Sea.

•    (L. a. omissus), invalid subspecies, an aberrant form of argentatus. Inland eastern Baltic, Finland and North-west Russia. 

•    L. a. argenteus, Iceland, north-western Europe.

• American Herring Gull  L. smithsonianus, North America.

• Vega Gull Larus vegae, northern Siberia, Bering Sea to China

• Heuglin's Gull Larus heuglini, two subspecies:

•    L. h. heuglini, White Sea, Kara Sea to NW India and Gulf of Aden

•    L. h. taimyrensis, Siberia

• Yellow-legged Gull Larus  michaellis, three subspecies:

•    Mediterranean Yellow-legged Gull, L. m. michaellis, southern Europe, Mediterranean, western France and Morocco.

•    Cantabrican Gull L. m. lusitanicus, north-western Spain and Portugal. Dubious subspecies.

•    Atlantic Gull L.  m. atlantis, eastern Atlantic Islands, Azores, Canaries, Madeira, Cape Verdes

• Caspian Gull Larus cachinnans, three subspecies:

•    Caspian Gull L. c. cachinnans, around Black Sea, Caspian Sea and Kazachstan.

•    Steppe or Baraba Gull L. c. barabensis, Central Asian steppes.

•    Mongolian Gull L. c. mongolicus, east Altai to Lake Baikal and Mongolia.

• Armenian gull Larus armenicus, Armenian lakes, eastern Turkey, north-west Iran.

• Lesser Black-backed Gull Larus fuscus, north-eastern Atlantic, expanding to North America, three subspecies:

•    Baltic Gull L. f. fuscus, Baltic, northern Norway to White Sea.

•    L. f. intermedius, southern Norway, Sweden, Denmark and north-west Spain.

•    L. f. graellsii, Iceland, British Isles, Faeroes, Netherlands, France and Spain.

• Kelp Gull Larus dominicanus, southern hemisphere species recently spreading northward: see Southern Gulls

• Iceland Gull Larus glaucoides: two subspecies:

•    Iceland Gull L. g. glaucoides, breeding Greenland, occasionally Iceland, wintering  northern Europe.

•    Kumlien's Gull L. g. kumlieni, breeding north-east Canada, wintering eastern North America.

• Thayer's Gull L.  thayeri, breeding Arctic Canada, western Greenland, wintering Pacific coast down to Baja California

• Adouin's Gull Larus adouinii, Mediterranean Sea

• Black-tailed or Japanese Gull Larus crassirostris, north-western Pacific

• Slaty backed Gull Larus schistisagus, north-western Pacific Ocean.

• Great Black-backed Gull Larus marinus, north Atlantic coasts.

• Glaucous Gull Larus hyperboreus: Three subspecies:

•    L. h. hyperboreus, North America towards Arctic Sea, Taimyr, Siberia .

•    L. h. barrovianus, Alaska, winters to California.

•    L. h. pallidssimus, East Siberia between Taimyr and Bering Sea.

•    (L. h. leucrectes): invalid subspecies.

• White-eyed Gull Larus leucophtalmus, north-western Indian Ocean.

• Sooty Gull Larus hemprichii, north-western Indian Ocean.

Sooty Gull Larus hemprichii Oman Culmen: 47.6 mm; total: 105.5 mm; unsexed adult

• Great Black-headed Gull or Pallas' Gull Larus ichtyaetus, from Black Sea to Mongolia, eastern Mediterranean.

• Glaucous-winged Gull Larus glaucescens, western North America

• Western Gull Larus occidentalis, western North America, two subspecies:

•    L. o. occidentalis, British Columbia to northern California.

•    L. o. wyemani, lower and southern California.

• Yellow-footed Gull Larus livens, North-west Mexico. Formerly subspecies of L. occidentalis

Ring-billed Gull Larus delawarensis Delaware Bay, USA Total: 94.1 mm, unsexed immature

•   Californian Gull Larus californicus, two subspecies:

•    L. c. californicus, western North America, inland and coastal.

•    L. c. albertaensis, southern NW Territories, northern Great Plains, Alberta to Manitoba.

• Ring-billed Gull Larus delawarensis, North America, inland and coastal.

• Common Gull Larus canus, three subspecies, almost circumpolar:

•    L. c. canus, Europe south to Mediterranean, North Africa to Persian Gulf.

•    L. c. henei, northern Siberia, central Russia to Baltic and Mediterranean and Caspian Sea. 

•    L. c. kamtchatchensis, eastern Siberia to Formosa.

• Mew Gull L.  brachyrynchus, Alaska and Canada to southern California.

• Heerman's Gull Larus heermanni, California USA to Mexico.

• Band-tailed Gull Larus belcheri,  vagrants have reached North America. See Southern Gulls

• Grey Gull Larus modestus, vagrant has reached North America

Lesser to small gulls

Genus Larus

• Brown-headed Gull Larus brunnicephalus, central southern Asia dispersing to more southern areas. 

• Grey-headed Gull Larus cirrocephalus, predominantly southern hemisphere, see Southern Gulls

• Black-headed Gull Larus ridibundus, temperate Europe and Asia, coastal and inland. 

• Slender-billed Gull Larus genei, Mediterranean, Asia Minor to Black en Caspian Sea.

• Bonaparte's Gull Larus philadelphia, North America, inland and coastal.

• Saunder's Gull Larus saundersi, Chinese coast, dispersing to Japan and Vietnam.

• Mediterranean Gull Larus melanocephalus, Mediterranean and western Europe.

• Relict Gull Larus relictus, central Asia

• Laughing Gull Larus atricilla, southern North America, Caribbean and Central America.

• Franklin's Gull Larus pipixcan, central North America, dispersing southward along Pacific coast.

• Little Gull Larus minutus, temperate Europe and Asia, inland and coastal.

• Sabine's Gull Larus sabini, high Arctic, dispersing to South  American and South African coasts

Non-Larus gulls

Genus Rissa

Two medium sized and very similar species from the higher latitudes of both major oceans. As the names say the coloration of the legs is the main difference between the species. The Black-legged Kittiwake is a little bit larger and has a slightly more slender bill  than its red-legged cousin. The two species overlap in distribution only in the Bering Sea area.

• Black-legged Kittiwake Rissa tridactyla, two subspecies:

•    R. t. tridactyla, Arctic Canada to Atlantic coast of Canada and Europe.

•    R. t. policaris, north-east Siberia to Kamchatka and Commander Is. and Aleutians.

• Red-legged Kittiwake Rissa brevirostris, Bering Sea and adjacent waters.

Genus Rhodostethia

• Ross's Gull Rhodostethia rosea, high Arctic of eastern Siberia, Canada and Greenland.

Genus Pagophila

Ivory Gull Pagophila eburna Greenland Culmen: 47.4 mm; total: 94.1 mm, unsexed adult

• Ivory Gull Pagophila eburnea, high Arctic, circumpolar.

Genus Creagrus 

• Swallow-tailed Gull Greagrus furcatus, vagrant to California. See Southern Gulls

Literature:

- Grant, P.J. 1986, Gulls, a guide to identification, Second Edition, T& A.D. Poyser,

- Malling Olsen K. & Larsson H. 2003, Gulls of Europe, Asia and North America, Helm , London 

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