Brachyramphus marmoratus

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

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Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	Charadriiformes	Alcidae

Scientific Name:

Brachyramphus marmoratus

Species Authority:

(Gmelin, 1789)

Common Name/s:

English

–

Marbled Murrelet

Taxonomic Notes:

Brachyramphus marmoratus (Sibley and Monroe 1990, 1993) has been split into B. marmoratus and B. perdix following AOU (1998).

Assessment Information [top]

Red List Category & Criteria:

Endangered A2c+3c+4c ver 3.1

Year Assessed:

2008

Assessor/s

BirdLife International

Evaluator/s:

Butchart, S., Capper, D. & Gilroy, J. (BirdLife International Red List Authority)

Justification:
This species is still abundant, but it is treated as Endangered because its population is estimated to have undergone a very rapid reduction over three generations (36 years), owing to a variety of threats. This decline is likely to continue.

History:

2005	–	Endangered
2004	–	Endangered
2000	–	Vulnerable
1994	–	Not Recognized
1988	–	Not Recognized

Geographic Range [top]

Range Description:	Brachyramphus marmoratus occurs in the USA and Canada in California, Oregon, Washington, British Columbia, south-east Alaska, Prince William Sound, Kenai Peninsula, Lower Cook Inlet, Barren Islands, Afognak and Kodiak Islands, the Alaska Peninsula and the Aleutians locally to Andreanof and Near Islands⁶. In Alaska (85% of the population), c.95% of 500,000-800,000 Brachyramphus spp. are probably B. marmoratus¹. The greatest historical decreases have been in Washington, Oregon and California, but populations in British Columbia and south-east Alaska are now most threatened¹³. The current annual decline in Washington, Oregon and California is 4-7%²¹, with a 50% decrease in Alaska in 1972-1992¹⁵, and 40% in parts of British Columbia in 1982-1992¹⁰.
Countries:	Native: Canada; United States Vagrant: Mexico
Range Map:	(click map to view full version)

Population [top]

Population:	Agler et al. (1998).
Population Trend:	Decreasing

Habitat and Ecology [top]

Habitat and Ecology:	It nests in old-growth trees (up to 60 km inland) and on the ground (sparsely where trees are absent, suboptimal)^{6,11,14,16,19}. Forest areas with multiple canopy layers and high mistletoe abundance are strongly preferred²². Breeding is mid-March to early September in California, but more compressed further north^6,7,8. The diet is sandlance, herring and, in winter, invertebrates⁶. It feeds in near-shore habitats up to 500 m offshore, in sheltered waters, lagoons and sometimes inland lakes^3,4,6,9. Daily movements to feeding areas can be up to 250 km²⁰.
Systems:	Terrestrial

Habitat and Ecology:

It nests in old-growth trees (up to 60 km inland) and on the ground (sparsely where trees are absent, suboptimal)^{6,11,14,16,19}. Forest areas with multiple canopy layers and high mistletoe abundance are strongly preferred²². Breeding is mid-March to early September in California, but more compressed further north^6,7,8. The diet is sandlance, herring and, in winter, invertebrates⁶. It feeds in near-shore habitats up to 500 m offshore, in sheltered waters, lagoons and sometimes inland lakes^3,4,6,9. Daily movements to feeding areas can be up to 250 km²⁰.

Systems:

Terrestrial

Threats [top]

Major Threat(s):	Many areas of remaining old-growth forest are slated for logging. Since the collapse of the Pacific sardine fishery, prey quality and abundance has declined, with lower trophic-level prey (e.g. krill) now dominating the pre-breeding diet²³. This has resulted in a lower proportion of individuals reaching breeding condition, and therefore lower population productivity. This factor, combined with high rates of nest predation by corvids, is thought to be the primary cause of recent declines²⁴. Nylon, monofilament gill-nets in shallow waters and oil-spills (e.g. Exxon Valdez and Nestucca) also cause considerable mortality^3,6,12,15.

Major Threat(s):

Many areas of remaining old-growth forest are slated for logging. Since the collapse of the Pacific sardine fishery, prey quality and abundance has declined, with lower trophic-level prey (e.g. krill) now dominating the pre-breeding diet²³. This has resulted in a lower proportion of individuals reaching breeding condition, and therefore lower population productivity. This factor, combined with high rates of nest predation by corvids, is thought to be the primary cause of recent declines²⁴. Nylon, monofilament gill-nets in shallow waters and oil-spills (e.g. Exxon Valdez and Nestucca) also cause considerable mortality^3,6,12,15.

Conservation Actions [top]

Conservation Actions:	Conservation actions underway: It is Threatened in all range states except Alaska. Detailed conservation recommendations were made in 1995¹⁷. Federal land-use is regulated, areas for management identified, and some temporarily removed from logging¹². In Canada there has been extensive research, a (now outdated) Recovery Plan and interim protection for nest-sites¹⁸. The Northwest Forest Plan (2006) is expected to ensure the protection of a large proportion of important habitats in the USA²⁵. In 1998, the Exxon Valdez Trustee Council protected 179 km² of Afognak Island². Conservation actions proposed: Survey potential nesting habitat. Collect data on the ratio of juvenile to adult birds from sites throughout the range, and monitor over time, as this is thought to be a reliable indicator of productivity²⁶Research means of improving the abundance of high quality food, e.g. small fish, during the pre-breeding period. Minimise damage to fish stocks and feeding areas¹⁸. Update the Canadian Recovery Plan¹⁸. Protect nesting habitat¹¹. Move campgrounds away from old-growth areas in Californian State Parks, in order to reduce predator populations in breeding areas. Reduce oil-spills, gill-net mortality and logging¹¹. List as Threatened in Alaska¹¹.

Conservation Actions:

Conservation actions underway:

It is Threatened in all range states except Alaska. Detailed conservation recommendations were made in 1995¹⁷. Federal land-use is regulated, areas for management identified, and some temporarily removed from logging¹². In Canada there has been extensive research, a (now outdated) Recovery Plan and interim protection for nest-sites¹⁸. The Northwest Forest Plan (2006) is expected to ensure the protection of a large proportion of important habitats in the USA²⁵. In 1998, the Exxon Valdez Trustee Council protected 179 km² of Afognak Island².

Conservation actions proposed:

Survey potential nesting habitat. Collect data on the ratio of juvenile to adult birds from sites throughout the range, and monitor over time, as this is thought to be a reliable indicator of productivity²⁶Research means of improving the abundance of high quality food, e.g. small fish, during the pre-breeding period. Minimise damage to fish stocks and feeding areas¹⁸. Update the Canadian Recovery Plan¹⁸. Protect nesting habitat¹¹. Move campgrounds away from old-growth areas in Californian State Parks, in order to reduce predator populations in breeding areas. Reduce oil-spills, gill-net mortality and logging¹¹. List as Threatened in Alaska¹¹.

Citation:	BirdLife International 2008. Brachyramphus marmoratus. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2. <www.iucnredlist.org>. Downloaded on 09 February 2010.
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