Ancient murrelet (Synthliboramphus antiquus) COSEWIC assessment and status report: chapter 5

Update
COSEWIC Status Report
on the
Ancient Murrelet
Synthliboramphus antiquus
in Canada
2004

Species Information

Name and Classification

The Ancient Murrelet (Synthliboramphus antiquus) belongs to the family Alcidae or the auks. The Ancient Murrelet is also known as ‘Guillemot à cou blanc’ in French and as ‘skinkana’ by the Haida of the Queen Charlotte Islands (Gaston 1992).

There are four species in the genus Synthliboramphus. The Ancient Murrelet’s closest relative is the Japanese Murrelet, S. wumizusume. The two other species are the Xantus’s Murrelet (S. hypoleucus) and Craveri’s Murrelet (S. craveri), both of which breed in the Baja California region (Gaston and Jones 1998). Of these four species, only the Ancient Murrelet breeds in Canada (Gaston 1994a).


Description

The Ancient Murrelet is a small auk, about 25 cm long and weighing from 200 to 250 g (Gaston 1994a). The males and females look very similar, both having a yellow-tipped bill, black head, chin, nape and throat, with fine black-and-white lines where the black of the head meets the gray of the body. They have a white underbelly and their flight feathers are dark slate.

During the breeding season, the back, upper wing and upper tail coverts are dove gray; the head, throat, and sides are black, with the rest of the underparts white, except a sooty brown line dividing belly from underwing. A fringe of long, filamentous, white feathers, forming a slight crest (Gaston 1994a) rings the crown.

In the fall, Ancient Murrelets undergo a full moult into non-breeding plumage, similar to breeding plumage except that the throat is white with sooty smudges on the chin, the tonsure of white feathers is reduced and the mantle is greyer (Gaston 1992). This plumage does not last long; as early as December the birds have moulted back to their breeding plumage (Gaston and Jones 1998).

In the summer, the Ancient Murrelet can be distinguished from Cassin’s Auklet (Ptychoramphus aleuticus) and the Marbled Murrelet (Brachyramphus marmoratus) by its black head and throat (Gaston 1994a). Immatures are similar to non-breeding adults (Gaston 1994a) except that they have no head streaks and have a white throat (National Geographic Society 1987; Gaston 1994).

 

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