Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub


    The marbled murrelet (Brachyramphus marmoratus) is a seabird in the family Alcidae that forages in nearshore waters of the Pacific Northwest, and nests in adjacent older-forest conifers within 80 km offshore. The species is of conservation concern due to habitat loss and declining numbers, and is listed as Threatened in British Columbia, Canada and in the United States portion of its range south of Canada. Recent monitoring in the United States indicated that murrelet numbers continued to decline there, especially in the waters of Washington State. To better understand this decline, and to inform conservation planning for the species, we evaluated how terrestrial and marine factors influence the distribution and abundance of the murrelet in coastal waters, including whether at-sea hotspots of murrelet abundance exist. Murrelet at-sea abundance and distribution were determined by surveys conducted annually from 2000 to 2012 in coastal waters from the United States–Canada border south to San Francisco Bay. We summarized mean and variance of murrelet density at the scale of 5-km segments of coastal waters throughout this area. We used a boosted regression tree analysis to investigate the contributions of a suite of marine and terrestrial attributes to at-seamurrelet abundance in each segment. We observed several regional hotspots of higher murrelet abundance at sea. Terrestrial attributes made the strongest contribution, especially the amount and cohesiveness of suitable nesting habitat in proximity to each segment, whereas marine attributes explained less of the spatial and temporal variations in murrelet abundance. At-sea hotspots of murrelet abundance therefore reflect not only suitable marine foraging habitat but primarily the proximity of suitable inland nesting habitat.

    Publication Notes

    • Visit PNW's Publication Request Page to request a hard copy of this publication.
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Raphael, Martin G.; Shirk, Andrew J.; Falxa, Gary A.; Pearson, Scott F. 2015. Habitat associations of marbled murrelets during the nesting season in nearshore waters along the Washington to California coast. Journal of Marine Systems. 146: 17-25.


    Google Scholar


    boosted regression, central place foraging, foraging habitat, habitat selection, hotspot marbled murrelet, nesting habitat, Pacific Northwest, USA, sea surface temperature

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page