Marbled murrelet (Brachyramphus marmoratus)
|Size||Length: 25 cm (2)|
The marbled murrelet is classified as Endangered (EN) by the IUCN Red List (1).
The marbled murrelet is a small, chubby seabird that has a very short neck (3). During the breeding season it has dark brown to blackish upperparts and a white belly and throat that are greatly mottled. During the winter the upperparts become grey, dark marks form on the sides of the breast and a white ring develops around the eye (2). Males and females are similar in appearance and size (3) (4). Juveniles are similar to the adult winter plumage, but with dusky mottling on the underparts (2). Vocalisations include a sharp ‘keer’ or low ‘kee’ (3).
The marbled murrelet is found along the western coast of the USA and Canada in California, Washington, Oregon, British Columbia, Alaska, Prince William Sound, Kenai Peninsula, Lower Cook Inlet, Barren Islands, Afognak and Kodiak Islands, the Alaska Peninsula and the Aleutians. Historically, the decline of this species has been most severe in Washington, Oregon and California; at present, however, the worst losses are occurring in British Columbia and Alaska (2).
The marbled murrelet is found near coastal waters, in bays and on mountains. It nests at high elevations in old growth forest, often at great distances from the coast (3). This species can be found up to 500 meters offshore (2).
The marbled murrelet feeds on fish such as sandlace and herring but feeds on invertebrates during winter (2). They forage singly, in pairs or in feeding flocks of a mix of different species (3).
In California, breeding occurs from mid-March to early September, but the season is shorter further north (2). The nest is built on large branches in high elevation forests or on the ground on some islands. Incubation of the yellowish spotted eggs takes around 30 days and the young chicks fledge after a further 28 days (3).
In many areas, the old-growth forests in which this murrelet breeds are subject to logging. Declines in areas where logging has not been a problem are thought to be due to a reduction in fish prey. Significant mortalities of this species have been caused by the birds becoming caught in gill-nets used in fishing, and by oil spills (2).
Conservation measures taken to date include the protection of some areas supporting the marbled murrelet from future logging. Detailed research has been carried out on this murrelet, and a recovery plan has been produced. Furthermore, 179 km² of Afognak Island has been protected since 1998 by the Exxon Valdex Trustee Council. Proposed measures include research, particularly into the feeding ecology of this bird in order to fully understand the threats facing it. It is vital that suitable nesting habitat is protected and that fish stocks in known feeding areas are not severely damaged (2).
For further information on the marbled murrelet see:
BirdLife International - Marbled murrelet:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
IUCN Red List 2007 (September, 2007)
BirdLife International (September, 2007)
Animal Diversity Web (March, 2004)
- Hull, C.L., Vanderkist, B.A., Lougheed, L.W., Kaiser, G.W. and Cooke, F. (2001) Morphometric variation in marbled murrelets, Brachyramphus marmoratus, in British Colombia. Northwestern Naturalist, 82(2): 41 - 51.