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Seasonal Movements, Winter Range Use, and Migratory Connectivity of the Black Oystercatcher Author(S): Matthew Johnson, Peter Clarkson, Michael I

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Seasonal Movements, Winter Range Use, and Migratory Connectivity of the Black Oystercatcher Author(S): Matthew Johnson, Peter Clarkson, Michael I Seasonal Movements, Winter Range use, and Migratory Connectivity of the Black Oystercatcher Author(s): Matthew Johnson, Peter Clarkson, Michael I. Goldstein, Susan M. Haig, Richard B. Lanctot, David F. Tessler and Denny Zwiefelhofer Source: The Condor, 112(4):731-743. 2010. Published By: Cooper Ornithological Society URL: http://www.bioone.org/doi/full/10.1525/cond.2010.090215 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. The Condor 112(4):731–743 ¡The Cooper Ornithological Society 2010 SEASONAL MOVEMENTS, WINTER RANGE USE, AND MIGRATORY CONNECTIVITY OF THE BLACK OYSTERCATCHER MATTHEW JOHNSON1,7, PETER CLARKSON2, MICHAEL I. GOLDSTEIN3, SUSAN M. HAIG1, RICHARD B. LANCTOT4, DAV I D F. TESSLER5, AND DENNY ZWIEFELHOFER6,8,9 1U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97330 2Pacific Rim National Park Reserve of Canada, P. O. Box 280, Ucluelet, BC V0R 3A0, Canada 3USDA Forest Service, Alaska Region, P. O. Box 21628, Juneau, AK 99802 4U.S. Fish and Wildlife Service, Migratory Bird Management, 1011 E. Tudor Rd. MS 201, Anchorage AK 99503 5Alaska Department of Fish and Game, Division of Wildlife Conservation, 333 Raspberry Road, Anchorage, AK 99518 6U.S. Fish and Wildlife Service, Kodiak National Wildlife Refuge, 1390 Buskin Rd., Kodiak, AK 99615 Abstract. The Black Oystercatcher (Haematopus bachmani) is an intertidal obligate along North America’s Pacific coast and a species of high conservation concern (population size 8900–11 000 individuals). Understand- ing birds’ movements and space use throughout the annual cycle has become paramount in the face of changing en- vironmental conditions, and intertidal species may be particularly vulnerable to habitat change due to anticipated sea-level rise associated with climate change and increasing coastal development. Conservation of the Black Oyster- catcher is hindered by a lack of information on the species’ nonbreeding distribution, seasonal movements, and habitat connectivity. Using satellite (n 19) and VHF (n 19) radio transmitters, we tracked Black Oystercatchers from five breeding sites (Vancouver Island, British Columbia; Kodiak Island, Prince William Sound, Middleton Island, and Juneau, Alaska) through one and one half annual cycles (May 2007–Dec 2008). We documented me- dium- to long-distance migration (range of migration distance 130–1667 km) in three populations (Prince William Sound, Middleton Island, and Juneau) and year-round residency in two others (Kodiak and Vancouver Island). We observed variation in the timing and length of migration by study site, and individual birds demonstrated fidelity to breeding and nonbreeding sites. We did not observe strong migratory connectivity. Migratory oystercatchers dis- tributed themselves widely along the coasts of British Columbia and southeast Alaska during winter. Results pro- vide baseline information on the Black Oystercatcher’s movements and space use throughout the annual cycle. Key words: Alaska, Black Oystercatcher, British Columbia, Haematopus bachmani, migration, migratory connectivity, satellite telemetry. Movimientos Inter-Estacionales, Uso de Áreas de Invernada y Conectividad Migratoria en Haematopus bachmani Resumen. El ostrero Haematopus bachmani está restringido al área intermareal de la costa del Pací- fico de América del Norte y es una especie que causa alta preocupación desde la perspectiva de conservación (tamaño poblacional 8900–11000 individuos). Comprender los movimientos de los individuos y su uso del espacio a lo largo del ciclo anual se ha convertido en un asunto de vital importancia porque las especies in- termareales pueden ser particularmente vulnerables a los cambios en las condiciones ambientales de los hábi- tats debidos a los aumentos en el nivel del mar que se anticipan con el cambio climático y al aumento en el desarrollo en las zonas costeras. La conservación de H. bachmani se ve limitada por la falta de información sobre la distribución no reproductiva de la especie, sobre movimientos estacionales y sobre conectividad del hábitat. Empleando transmisores de satélite (n 19) y de radio VHF (n 19), seguimos a individuos de la es- pecie provenientes de cinco sitios reproductivos (Vancouver Island, British Columbia; Kodiak Island, Prince Wil- liam Sound, Middleton Island y Juneau, Alaska) durante un ciclo anual y medio (mayo de 2007 a diciembre de 2008). Documentamos migración a distancias medias y largas (rango de distancia de migración 130–1667 km) en tres poblaciones (Prince William Sound, Middleton Island y Juneau) y residencia a lo largo del año en otras dos (Kodiak y Vancouver Island). Observamos variación entre sitios de estudio en el momento en que tuvo lugar la migración y en su extensión, y los individuos demostraron fidelidad a los sitios reproductivos y no reproductivos. No observamos una conectividad migratoria fuerte. Los ostreros migratorios se distribuyeron ampliamente en las costas de British Columbia y del sureste de Alaska durante el invierno. Los resultados brindan información básica sobre los movimientos y el uso del espacio por parte de H. bachmani a lo largo de su ciclo anual. Manuscript received 10 November 2009; accepted 22 June 2010. 7E-mail: [email protected] 8Current address: P. O. Box 2100, Kodiak, AK 99615. 9Co-authors are listed alphabetically. The Condor, Vol. 112, Number 4, pages 731–743. ISSN 0010-5422, electronic ISSN 1938-5422. 2010 by The Cooper Ornithological Society. All rights reserved. Please direct all requests for permission to photocopy or reproduce article content through the University of California Press’s Rights and Permissions website, http://www.ucpressjournals.com/ reprintInfo.asp. DOI: 10.1525/cond.2010.090215 731 732 MATTHEW JOHNSON ET AL. breed in Alaska abandon breeding areas in the winter (Wik INTRODUCTION and Streveler 1967, Andres and Falxa 1995, van Vliet 2005). The importance of understanding birds’ space use and move- Repeated winter surveys of Middleton Island, Alaska, found ment patterns throughout the annual cycle has gained promi- none of the approximately 700 oystercatchers present during nence over the past 20 years (Haig et al. 1997, 1998, 2002, the breeding season (Gill et al. 2004, Tessler et al. 2007). A Webster et al. 2002, Marra et al. 2006). Further development winter survey in Prince William Sound detected only 25% of of tracking technologies such as satellite transmitters, geolo- Black Oystercatchers that bred there during summer (Andres cators, molecular markers, trace elements, and stable isotopes 1994). Furthermore, three Black Oystercatchers (one adult in has resulted in an explosion of research aimed at understand- 2004 and two chicks in 2005) banded in Alaska (Middleton ing avian life histories in a more complete way (Gill et al. 2008, Island, Glacier Bay and Kenai Fjords national parks, respec- Szep et al. 2009, Carlisle et al. 2009). The Black Oystercatcher tively) were resighted during winter 2006 in British Colum- (Haematopus bachmani) is a relatively large (500–700 g), long- bia, Canada (adult and unrelated young on Vancouver Island, lived (15 years) shorebird of the family Haematopodidae immature on Queen Charlotte Islands; Tessler et al. 2007). Al- which occurs along North America’s Pacific coast from the though two of these observations may represent natal disper- Aleutian Islands to Baja California (Andres and Falxa 1995, sal and not migration, they all suggest large-scale movements. Tessler et al. 2007). As an intertidal obligate, the Black Oys- In contrast, winter and summer surveys of Kodiak Island, tercatcher is dependent year round on marine shorelines, Alaska, each produced approximately 1700 oystercatchers, where its invertebrate prey, including primarily bivalves and suggesting a resident population (Tessler et al. 2007). other mollusks (limpets, whelks, and chitons), are abundant Knowledge of migratory connectivity, the geographic (Jehl 1985). The Black Oystercatcher is a species of high con- linkage of individuals or populations at different stages of the servation concern throughout its range because of its small annual cycle, is essential for effective monitoring and con- population size (8900–11 000 individuals) and threats to the servation of wildlife (Webster et al. 2002). Across its range, birds and their coastal habitats throughout the annual cycle patterns of movement of migratory populations of the closely (Donaldson et al. 2000, Drut and Buchanan 2000, Brown et related Eurasian Oystercatcher (H. ostralegus) are complex. al. 2001, Hickey et al. 2003, USSCP 2004, Tessler et al. 2007). For some breeding populations, migratory connectivity
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