Genus CepphusThe three species of this genus are somewhat smaller than the former species and can be separated immediately by their bright red legs. Body plumages are variable from almost black – except for the white wing patches in two of them – to an almost white plumage of some subspecies in winter. Ranges only meet in the Bering Strait area. In both species subspecies differ by size, color patterns and wing measurements. The monotypic Spectacled Guillemot lives in the western North Pacific and is the largest of the three.
Their skulls are considerably smaller than those of the Murres and lack the orbital ridge.
- Black Guillemot or Tystie Cepphus grylle. Up to seven subspecies:
- C. g. grylle. Baltic Sea.
- C. g. ultimus. Eastern Canadian Arctic and NW Greenland.
- C. g. mandtii. High Arctic of Spitzbergen.
- C. g. arctica. Sub-arctic of the eastern Atlantic.
- C. g. islandica. Iceland.
- C. g. faeroensis. Faeroe Is.
- C. g. atlantis. British Isles.
- Pigeon Guillemot Cepphus culumba. Up to five subspecies, all from the Pacific:
- C. c. eureka, Californian and Oregon coast.
- C. c. adianta. Washington, Alaska coast to central Aleutian Is.
- C. c. kaiurka. Adak I. west to the Commander Is.
- C. c. culumba. Bering sea coast of Siberia down to Kamchatka and coastal Alaska.
- C. c. snowi. Kurile Is.
- Spectacled Guillemot Cepphus carbo, no subspecies, Kamchatka peninsula to Korea.
Black Guillemot Cepphus grylle islandica Iceland
Culmen: 29.3 mm; total: 78.0 mm; unsexed adult
Two rather similar auklets with dark brown mottled upperparts with distinctive winterplumages. In spite of their abundance in certain areas very little is known about the breeding biology of these species. They are of similar size, but the bill of the Kittlitz's Murrelet is much shorter than the Marbled's.
- Marbled Murrelet Brachyramphus marmoratus. Two subspecies differing only slightly in measurements:
- B. m. marmoratus. From North California to central Aleutian Is.
- B. m. perdix. From Aleutians south to northern Japan, Hokkaido.
- Kittlitz's Murrelet Brachyramphus brevirostris, Aleutians, Alaska and Bering Strait, dispersing to Washington and Kurile Is.
Five species of auklets with quite different bills. The Ancient and the Japanese are rather similar birds but the Ancient has a white bill with a black base, the Crested an all white bill. The other two species both have all black bills of which the Craveri's Murrelet has the longest.
- Guadelupe Murrelet Synthliboramphus hypoleucus. California, Oregon and Washington coast. Recent split of Xantus' Murrelet S. h. hypoleucos.
- Scripp's Murrelet S. h. scrippsi. breeding islands off Los Angeles. Recent split of Xantus' Murrelet S. h. scrippsi.
- Craveri's Murrelet Synthliboramphus craveri, inshore waters Gulf of California dispersing up to Los Angeles.
- Ancient Murrelet Synthliboramphus antiquum, breeding Alaska and north-east Asian coast, wintering to California.
- Crested or Japanese Murrelet Synthliboramphus wumizusum, endemic to southern Japan and off Korea, dispersing widely around Japan.