Species: Brachyramphus marmoratus
Marbled Murrelet
Species
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Encyclopedia of Puget Sound
A chunky seabird with a black bill and an entirely dark tail. Breeding adult is dark brown above, heavily mottled below. In winter plumage, white below, with white scapular streak on otherwise dark upperparts. Juvenile resembles winter adult but has dusky-mottled underparts, which become mostly white by the first winter. (NGS 1983).
Science Review:
Articles:
Marbled murrelets are a rare sight in Puget Sound. The threatened birds have declined severely in California, Oregon, and Washington, and biologists are intrigued by their summer presence in Commencement Bay.
For years now, scientists have been braving the cold winter waters of Puget Sound to study one of the region's most enigmatic seabirds, the marbled murrelet. Listed as threatened under the Endangered Species Act in Washington, Oregon, and California, marbled murrelets nest in old-growth forests but find their food at sea. Much research on the birds has centered around the spring and summer breeding season, but less is known about what the murrelets do in winter. That puzzle prompted a team of scientists from the Washington Department of Fish and Wildlife to head out on the water last January. Writer and biologist Eric Wagner joined the expedition and brought back these notes from the field.
Why did all the grebes leave? Where did they go? And what does their disappearance say about the health of the Salish Sea? Seasonal declines among some regional bird species could hold important clues to the overall health of the ecosystem.
A December 2013 report identifies marine and terrestrial bird species for use as indicators within the Puget Sound Partnership's "Vital Signs" for ecosystem health.
This article was originally published by the Washington Department of Fish and Wildlife as part of its annual report Threatened and Endangered Wildlife in Washington.
More than 70 bird species regularly utilize Puget Sound during some or all stages of their life histories, but only a portion of these are actively being investigated.
Classification
Kingdom
Animalia
Phylum
Craniata
Class
Aves
Order
Charadriiformes
Family
Alcidae
Genus
Brachyramphus
NatureServe
Classification
Other Global Common Names
guillemot marbré
Informal Taxonomy
<p>Animals, Vertebrates - Birds - Other Birds</p>
Formal Taxonomy
Animalia - Craniata - Aves - Charadriiformes - Alcidae - Brachyramphus - Genetic data presented by Piatt et al. (2007) indicate that the marbled murrelet is represented by three populations, comprising birds in (1) the central and western Aleutian Islands, (2) central California, and (3) the center of the range from the eastern Aleutians to northern California.
Ecology and Life History
A chunky seabird with a black bill and an entirely dark tail. Breeding adult is dark brown above, heavily mottled below. In winter plumage, white below, with white scapular streak on otherwise dark upperparts. Juvenile resembles winter adult but has dusky-mottled underparts, which become mostly white by the first winter. (NGS 1983).
Short General Description
A robin-sized seabird (murrelet).
Migration
<p>true - true - false</p>
Non-migrant
true
Locally Migrant
true
Food Comments
Diet includes fishes (sandlance, capelin, herring, etc.), crustaceans (mysids, euphausiids), mollusks. In British Columbia, adult diet during the breeding season is mostly fishes, primarily Pacific Sandlance and Pacific Herring; euphausiids are important in spring at Langara Island; sandlance are the prey most frequently fed to nestlings (Rodway et al., in Carter and Morrison 1992). May feed exclusively on freshwater prey for period of several weeks in some areas; feeds on fingerling Sockeye Salmon and salmon fry in some British Columbia lakes (Carter and Sealy 1986). Foraging occurs mainly in waters up to 80 m deep and up to 2 km from shore. Foraging dives may be up to about 30 m below surface.
Reproduction Comments
Nesting season: late March to late September; downy young, and fledged juveniles have been observed June-September. Activity in forest nesting areas is highest from mid-April through late July in California and Oregon, early May through early August in Washington, and mid-May through early August in Alaska (see Levy 1993). Clutch size is 1. Incubation lasts about 30 days, by both sexes alternately in 24-hr shifts. Nestling is visited and fed by parent 2-4 times each day, fledges in 27-40 days (Marshall 1988, Levy 1993). Appears to nest semicolonially (see USFWS 1994). In a study on the British Columbia coast, foraging distance from nest (i.e. energy spent commuting) had no influence on nesting success (Hull et al. 2001). Generation time is around 10 years (COSEWIC 2012).
Ecology Comments
Solitary, or in pairs, small groups, or loose aggregations. In most areas, generally does not flock with other birds, but may participate in mixed-species feeding flocks in the absence of interference from larger diving birds (Mahon et al. 1992). <br><br>The only confirmed record of predation on an adult at its nest involved a Sharp-shinned Hawk in Alaskan old-growth forest (Marks and Naslund 1994). <br><br>Species has high fidelity to nesting areas and nest trees (see Nelson 1997).<br><br>Despite the urgent need for an assessment of the demographic state of populations, the species is so secretive that reliable estimates of the required vital rates are rare. Survival estimates obtained through capture-recapture data from a population in British Columbia were 0.8289 and 0.9289, based on different samples corresponding to two capture techniques. The study area had been and continues to be heavily logged (Cam et al. 2003).
Length
25
Weight
222
Conservation Status
NatureServe Global Status Rank
G3G4
Global Status Last Reviewed
2008-10-07
Global Status Last Changed
2001-01-12
Distribution
Conservation Status Map
<img src="http://www.natureserve.org/explorer/servlet/GetMapGif?CA.BC=S3&US.AK=S3&US.CA=S1&US.OR=S2&US.WA=S3" alt="Conservation Status Map" style="width: 475px; height: auto;" />
Global Range
G - 200,000-2,500,000 square km (about 80,000-1,000,000 square miles) - G - Breeding range extends from the western Aleutian Islands through coastal southern and southeastern Alaska, British Columbia (up to 100 kilometers inland), Washington, Oregon, and northern central California (mainly Del Norte and northern Humboldt counties to 15 km inland, southcentral Humboldt County 20-40 km inland, and southern San Mateo and northern Santa Cruz counties up to 20 km inland; Carter and Erickson in Carter and Morrison 1992); few occupied sites are known between Tillamook County in Oregon and the Olympic Peninsula in Washington (USFWS 1994). See USFWS (1994) and Federal Register (10 August 1995) for maps of proposed Critical Habitat in California, Oregon, and Washington. During the nonbreeding season, the range extends from southern Alaska south to central California, mostly adjacent to known or suspected nesting areas. Most of the Alaskan population is concentrated offshore of large tracts of coastal coniferous forests in southeastern Alaska (Alexander Archipelago), Prince William Sound, and the Kodiak Archipelago (Piatt and Ford 1993). See Marshall (1988), Carter and Morrison (1992), and Piatt et al. (2007) for further details for specific states and provinces.<br><br>Coded range extent pertains to breeding range.
Global Range Code
G
Global Range Description
200,000-2,500,000 square km (about 80,000-1,000,000 square miles)