Don Edwards San Francisco Bay National Wildlife Refuge

The Black-headed Gull (Chroicocephalus ridibundus) is a small gull which breeds in much of Europe and Asia, and also in coastal eastern Canada. Most of the population is migratory, wintering further south, but some birds in the milder westernmost areas of Europe are resident. Some birds will also spend the winter in northeastern North America, where it was formerly known as the Common Black-headed Gull. As is the case with many gulls, it had previously been... less ↑

The Little Gull (Hydrocoloeus minutus or Larus minutus), is a small gull which breeds in northern Europe and Asia. It also has small colonies in parts of southern Canada. It is migratory, wintering on coasts in western Europe, the Mediterranean and (in small numbers) the northeast USA; in recent years non-breeding birds have summered in western Europe in increasing numbers. As is the case with many gulls, it has traditionally been placed in the genus Larus.... less ↑

The California Least Tern, Sterna antillarum browni, is a subspecies of Least Tern that breeds primarily in bays of the Pacific Ocean within a very limited range of Southern California, in San Francisco Bay and in and extreme northern Mexico. This migratory bird is a U.S. federally listed endangered subspecies. The total population of the subspecies amounted to 582 breeding pairs in 1974, when census work on this bird began. While numbers have gradually increased with... less ↑

The European Herring Gull (Larus argentatus) is a large gull (up to 26 inches or 66 cm long). One of the best known of all gulls along the shores of western Europe, it was once abundant. It breeds across Northern Europe, Western Europe, Central Europe, Eastern Europe, Scandinavia and the Baltic states. Some European Herring Gulls, especially those resident in colder areas, migrate further south in winter, but many are permanent residents, e.g. in the British Isles, Iceland,... less ↑

The Common Gull (European and Asian subspecies; see below) or Mew Gull (North American subspecies) Larus canus is a medium-sized gull which breeds in northern Asia, northern Europe and northwestern North America. It migrates further south in winter. Its name does not indicate that it is an abundant species, but that during the winter it feeds on common land, short pasture used for grazing. less ↑

The Glaucous-winged Gull (Larus glaucescens) is a large, white-headed gull residing from the western coast of Alaska to the coast of Washington. It also breeds on the northwest coast of Alaska, in the summertime. During non-breeding seasons they can be found along the coast of California. It is a close relative of the Western Gull and frequently hybridizes with it, resulting in identification problems—particularly in the Puget Sound area. This species also hybridizes regularly with the... less ↑

The Heermann's Gull (Larus heermanni) is a gull resident in the United States, Mexico and extreme southwestern British Columbia. Of the current population of about 150,000 pairs, 90% nest on the island of Isla Rasa off Baja California in the Gulf of California, with smaller colonies as far north as California and as far south as Nayarit. After breeding, birds commonly disperse to central California, and less commonly north as far as British Columbia and south... less ↑

The Glaucous Gull (Larus hyperboreus) is a large gull which breeds in the Arctic regions of the northern hemisphere and the Atlantic coasts of Europe. It is migratory, wintering from in the North Atlantic and North Pacific oceans as far south as the British Isles and northernmost states of the USA, also on the Great Lakes. A few birds sometimes reach the southern USA and northern Mexico. less ↑

The Western Gull (Larus occidentalis) is a large white-headed gull that lives on the western coast of North America. It was previously considered conspecific, the same species, with the Yellow-footed Gull (Larus livens) of the Gulf of California. The Western Gull ranges from British Columbia, Canada to Baja California, Mexico, and because of its convenient colonies on the coast of California it is well studied. Despite being a well-known bird species on the West Coast of... less ↑

The Slaty-backed Gull (Larus schistisagus) is a large white-headed gull that breeds on the western coast of Alaska but travels widely during nonbreeding seasons. It is similar in appearance to the Western Gull and the Glaucous-winged Gull. Another alternate name is Pacific Gull, though this also applies to a southern hemisphere species, Larus pacificus. Claims have been made as to its (sometimes occasional) presence throughout North America as well as the eastern coast of Asia. On... less ↑

The Thayer's Gull (Larus thayeri) is a large gull native to North America that breeds in the Arctic islands of Canada and primarily winters on the Pacific coast, from southern Alaska to the Gulf of California, though there are also wintering populations on the Great Lakes and the upper Mississippi River. The species has occurred a vagrant to Tamaulipas, Mexico,1 Japan,3 Denmark, and other parts of western Europe. less ↑

The Common Tern (Sterna hirundo) is a seabird of the tern family Sternidae. This bird has a circumpolar distribution, its four subspecies breeding in temperate and subarctic regions of Europe, Asia and North America. It is strongly migratory, wintering in coastal tropical and subtropical regions. Breeding adults have light grey upperparts, white to very light grey underparts, a black cap, orange-red legs, and a narrow pointed bill. Depending on the subspecies, the bill may be mostly... less ↑

The Arctic Tern (Sterna paradisaea) is a seabird of the tern family Sternidae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe, Asia, and North America (as far south as Brittany and Massachusetts). The species is strongly migratory, seeing two summers each year as it migrates from its northern breeding grounds along a winding route to the oceans around Antarctica and back, a round trip of about 70,900 km (c. 44,300... less ↑

The Black Skimmer (Rynchops niger) is a tern-like seabird, one of three very similar birds species in the skimmer family. It breeds in North and South America. Northern populations winter in the warmer waters of the Caribbean and the tropical and subtropical Pacific coasts, but the South American races make only shorter movements in response to annual floods which extend their feeding areas in the river shallows. less ↑

The Sabine's Gull (Xema sabini), also known as the Fork-tailed gull or Xeme, is a small gull. Its generic placement is disputed; some authors treat it as the sole species in the genus Xema as Xema sabini, while others retain it in the genus Larus as Larus sabini. It breeds in the Arctic and has a circumpolar distribution through northernmost North America and Eurasia. It migrates south in autumn; most of the population winters at sea less ↑