Status Assessment of Laysan and Black-Footed Albatrosses, North Pacific Ocean, 1923–2005 Scientific Investigations Report 2009-5131 U.S. Department of the Interior U.S. Geological Survey Cover: Photograph of Laysan and black-footed albatrosses. Photograph taken by Eric VanderWerf, Pacific Rim Conservation. Status Assessment of Laysan and Black-Footed Albatrosses, North Pacific Ocean, 1923–2005 By Javier A. Arata, University of Massachusetts-Amherst, Paul R. Sievert, U.S. Geological Survey, and Maura B. Naughton, U.S. Fish and Wildlife Service Scientific Investigations Report 2009-5131 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia: 2009 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Arata, J.A., Sievert, P.R., and Naughton, M.B., 2009, Status assessment of Laysan and black-footed albatrosses, North Pacific Ocean, 1923–2005: U.S. Geological Survey Scientific Investigations Report 2009-5131, 80 p. iii Contents Executive Summary .......................................................................................................................................1 Introduction.....................................................................................................................................................2 Taxonomy ........................................................................................................................................................4 Legal and Conservation Status ....................................................................................................................4 Species’ Descriptions ...................................................................................................................................5 Geographic Distribution ................................................................................................................................5 Breeding Colonies.................................................................................................................................5 At-Sea Distribution ..............................................................................................................................5 At Sea: Breeding Albatrosses ...................................................................................................6 At Sea: Non-Breeding Albatrosses ..........................................................................................7 Natural History ...............................................................................................................................................8 Laysan Albatross...................................................................................................................................8 Breeding Cycle .............................................................................................................................8 Nests and Nest Spacing .............................................................................................................8 Breeding Site and Mate Fidelity ................................................................................................8 Demography and Limiting Factors ............................................................................................8 Predators .......................................................................................................................................9 Diet and Foraging Behavior .....................................................................................................10 Black-Footed Albatross .....................................................................................................................10 Breeding Cycle ...........................................................................................................................10 Nests and Nest Spacing ...........................................................................................................10 Breeding Site and Mate Fidelity ..............................................................................................11 Demography and Limiting Factors ..........................................................................................11 Predators .....................................................................................................................................11 Diet and Foraging Behavior .....................................................................................................11 Habitat Requirements..................................................................................................................................12 Threats ...........................................................................................................................................................12 Fishery Bycatch...................................................................................................................................12 Description of the Fisheries .....................................................................................................12 Bycatch Estimation ....................................................................................................................14 Predation ..............................................................................................................................................16 Introduced Species ............................................................................................................................16 Habitat Loss and Degradation ..........................................................................................................16 Invasive Plants ...........................................................................................................................16 Urban and Military Development ............................................................................................16 Conflicts with Military Activities ......................................................................................................17 iv Contents—Continued Threats—Continued Pesticides and Other Contaminants ................................................................................................18 Metals .........................................................................................................................................18 Organochlorine Contaminants .................................................................................................18 Plastics .................................................................................................................................................20 Disease .................................................................................................................................................20 Population Size and Isolation ...........................................................................................................20 Climate Change ...................................................................................................................................21 Monitoring and Management Activities ..................................................................................................21 Monitoring ...........................................................................................................................................21 Breeding Surveys.......................................................................................................................21 Bycatch Monitoring ...................................................................................................................22 Management Activities ......................................................................................................................22 Protection of Nesting Islands ..................................................................................................22 Habitat and Vegetation Management ....................................................................................22 Predator Management ..............................................................................................................23 Fishery Management ................................................................................................................23 Migratory Bird Treaty Act .........................................................................................................23 Population Status and Trends ...................................................................................................................23 Population Analysis Methods ...........................................................................................................24