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Marbled Murrelet

Marbled Murrelet

Scientific name:  Brachyramphus marmoratus

Status: Threatened

Critical Habitat: Designated

Listing: In 1992, the Washington, Oregon, and California population of the marbled murrelet was federally listed as threatened. In October 2008, USFWS initiated a 12-month status review of the species as a result of a petition to delist. The 12-month finding concluded, in January 2010, that the murrelet needs continued protection and will retain its status as a threatened species.

Critical Habitat:  Critical habitat was designated in 1996 and revised in 2011.  The current designation consists of approximately 3,698,100 acres in Washington, Oregon, and California.

  • Historical Status and Current Trends

    The marbled murrelet ranges from the Aleutian Islands and southern Alaska to central California. The largest portion of the population occurs in Alaska and British Columbia. The listed portion of the species range extends from the Canadian border south to central California. Loss of viable nesting habitat (older forest) is thought to be a primary factor responsible for declining marbled murrelet populations in Washington, Oregon, and California. In Washington, in the marine environment, this species occurs in the greatest numbers in the Straits of Juan de Fuca and San Juan Islands. Current estimates indicate that the population continues to decline in Washington at a rate of about 5% per year. It is unlikely that population numbers will increase rapidly due to the naturally low reproductive rate and the continued loss of nesting habitat. Recovery of the species is likely to take decades.

    Habitat

    The marbled murrelet is a small, robin-sized, diving seabird that feeds primarily on fish and invertebrates in near-shore marine waters. It spends the majority of its time on the ocean, roosting and feeding, but comes inland up to 70 miles (113 kilometers ) to nest in forest stands with old growth forest characteristics. These dense shady forests are generally characterized by large trees with large branches or deformities that are used as nest platforms. Murrelets nest in stands varying in size from several acres to thousands of acres. However, larger, unfragmented stands of old growth appear to be the highest quality habitat for marbled murrelet nesting.

    Life History

    Marbled murrelets nest from mid-April to late September. The sexually mature adult murrelet (at age 2 or 3 of an average 15-year lifespan) lays a single egg on a mossy limb of an old-growth conifer tree. Both sexes incubate the egg in alternating 24-hour shifts for approximately 30 days. Murrelet chicks are virtually helpless and rely on the adults for food. The adults feed the chick at least once per day, flying in (primarily at dawn and dusk) from feeding on the ocean, carrying one fish at a time. The young fledge from the nest in about 28 days and appear to fly directly to the sea upon leaving the nest. Marbled murrelets have a naturally low reproductive rate because they lay only one egg per nest and not all adults nest every year.

    Reasons for Decline

    The primary cause of marbled murrelet population decline is the loss and modification of nesting habitat in old growth and mature forests through commercial timber harvests, human-induced fires, and land conversions, and to a lesser degree, through natural causes such as wild fires and wind storms. In general, forest management practices that maximize timber production cut and replant forest stands every 40 to 60 years. Since it takes 100 to 250 years to grow marbled murrelet nesting habitat, this time frame frequently does not allow old-growth characteristics to develop, thus eliminating large areas from providing future nesting habitat. Continued harvest of old growth and mature forests also perpetuates the loss and fragmentation of remaining habitat. Changing the existing habitat by fragmenting the forest into small patches of suitable habitat surrounded by open space also affects the habitat quality. Increased forest fragmentation can reduce nesting success by allowing increased predation of nests by raptors (great horned owls, sharp-shinned hawks) and corvids (jays, ravens, crows). In the murrelet's marine habitat, oil spills and gill-net fishing also threaten the population. Recent oil spills off the coast of California and Oregon have contributed to direct mortality of marbled murrelets and other seabirds.

    Conservation Measures

    Although most murrelet nesting habitat on private lands has been eliminated by logging, suitable habitat remains on federal- and state-owned lands. Areas of critical habitat have been designated within the three-state area to protect habitat and promote the recovery of the species. Over the next 50 to 100 years, the protected areas on federal lands, which are generally managed under the Northwest Forest Plan, should provide for an increase in suitable nesting habitat. Although timber continues to be harvested, timber sale programs on federal lands require consultation with the U.S. Fish and Wildlife Service to review and assess the potential impacts of the timber harvests on the marbled murrelet. In 1997, the Fish and Wildlife Service approved a recovery plan for the marbled murrelet that specified actions necessary to halt the decline of the species in the three-state area.

    Five-year reviews were completed for this species in 2004 and 2009.

    References and Links

    Northwest Interagency ESA Website: ESA and Streamlined Consultation documents, important references and links, and other materials Website

    Status Reviews

    Northwest Forest Plan—The first 20 years (1994-2013) http://www.reo.gov/monitoring/reports/20yr-report/MAMU%20GTR_for%20posting_26May2015.pdf

    Status Review of the Marbled Murrelet in Alaska and British Columbia. USGS 2006. http://pubs.usgs.gov/of/2006/1387/

    Survey Protocol

    Inland Survey Protocol: Methods for Surveying Marbled Murrelets in Forests: A Revised Protocol for Land Management and Research. January 2003. Report

    https://www.fws.gov/arcata/es/birds/MM/documents/2003%20PSG%20Murrelet%20Inland%20Survey%20Protocol.pdf

    Other Marbled Murrelet Websites

    U.S. Geological Survey: Patuxent Bird Identification Center 
    Northwest Forest Plan Information

    U.S. Geological Survey: Patuxent Bird Identification Center 
    Northwest Forest Plan Information

    Regional Ecosystem Office: Northwest Forest Plan Website 

    Regional Ecosystem Office: Northwest Forest Plan Website 

    USDA Forest Service, Pacific Region: Northwest Forest Plan Website

    USDA Forest Service, Pacific Region: Northwest Forest Plan Website

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