Volume 51, No. 1

Search by author or title:

Stable isotope-determined diets of Black Oystercatchers Haematopus bachmani in the Northern Gulf of Alaska


1National Oceanic and Atmospheric Administration, National Sea Grant Program, 1007 W. 3rd Ave, Anchorage, Alaska 99501, United States
2US Fish and Wildlife Service, 1011 E. Tudor Road, Anchorage, Alaska 99503, United States
3National Park Service, 240 W. 5
th Avenue, Anchorage, Alaska 99501, United States
4Department of Biological Sciences, University of Alaska, 3211 Providence Drive, Anchorage, Alaska 99508, United States
5Ecology and Genetics Research Unit, University of Oulu, 90570, Finland
6Arctic Initiative, Belfer Center for Science and International Affairs, Harvard Kennedy School, 79 John F. Kennedy St. Cambridge, Massachusetts 02138, United States *(


CARNEY, B., TESSLER, D., COLETTI, H., WELKER, J.M., & CAUSEY, D. 2023. Stable isotope-determined diets of Black Oystercatchers Haematopus bachmani in the Northern Gulf of Alaska. Marine Ornithology 51: 123 - 135

Received 15 July 2022, accepted 28 December 2022

Date Published: 2023/04/15
Date Online: 2023/04/10
Key words: Black Oystercatcher, Haematopus bachmani, stable isotopes, diet, Gulf of Alaska


Black Oystercatchers Haematopus bachmani (BLOY) feed on intertidal invertebrates along coasts of the northern Gulf of Alaska and elsewhere. Details of their feeding ecology have only been marginally delineated, however, and as population sizes are small and limited geographically, rapid ecological changes may alter their prey base, placing BLOY resiliency in jeopardy. We examined the diets of BLOYs occupying the coast at three sites in Southeast Alaska using stable isotope analysis of carbon (δ13C) and nitrogen (δ15N) to answer the following three questions: (1) what are the diet proportions of prey groups consumed at different locations along the northern Gulf of Alaska; (2) how do individual diets vary; and (3) how do current diets compare to those of the past? Results indicate that: (a) the diet of individual BLOYs was approximately ~52% mussels Mytilus trossulus or other filter feeders, ~41% limpets Lottia spp. or other kelp and algal grazers, and ~5% dogwinkles Nucella spp. or other secondary consumers; (b) little variation in diet existed between seasons or locality; and (c) diets of adults during summer have varied little over the last 100 years. These findings indicate that BLOYs have a very specialized feeding niche that has not changed substantially over time. We discuss the possibility that changing ocean processes may alter the abundance of filter feeders and ultimately have effects on BLOY success in the study region.


ANDRES, B.A. & FALXA, G.A. 2020. Black Oystercatcher (Haematopus bachmani), version 1.0. In:. POOLE, A.F. & GILL, F.B. (Eds.). The Birds of North America. Ithaca, USA: Cornell Laboratory of Ornithology.

BEARHOP, S., WALDRON, S., VOTIER, S.C. & FURNESS, R.W. 2002. Factors that influence assimilation rates and fractionation of nitrogen and carbon stable isotopes in avian blood and feathers. Physiological and Biochemical Zoology 75: 451-458. doi:10.1086/342800

BECKER, B.H. & BESSINGER, S.R. 2006. Centennial decline in the trophic level of an endangered seabird after fisheries decline. Conservation Biology 20: 470-479. doi:10.1111/j.1523-1739.2006.00379.x

BENSON, J. & SURYAN, R.M. 1999. A leg-noose for capturing adult kittiwakes at the nest. Journal of Field Ornithology 70: 393-399.

BUGONI, L., MCGILL, R.A.R. & FURNESS, R.W. 2008. Effects of preservation methods on stable isotope signatures in bird tissues. Rapid Communications in Mass Spectrometry 22: 2457-2462. doi:10.1002/rcm.3633

CAUSEY, D., WELKER, J.M., BURNHAM, K.K., PADULA, V.M., & BARGMANN, N.A. 2014. Fine-scale temporal and spatial patterns of a high arctic marine bird community. In: MUETER, F.J., DICKSON, D.M.S., HUNTINGTON, H.P. ET AL. (Eds.). Responses of Arctic Marine Ecosystems to Climate Change. Fairbanks, USA: Alaska Sea Grant, University Alaska Fairbanks.

CAUT, S., ANGULO, E. & COURCHAMP, F. 2009. Variation in discrimination factors (Δ15N and Δ13C): the effect of diet isotopic values and applications for diet reconstruction. Journal of Applied Ecology 46: 443-453. doi:10.1111/j.1365-2664.2009.01620.x

CHEREL, Y., HOBSON, K.A. & HASSANI, S. 2005. Isotopic discrimination between food and blood and feathers of captive penguins: implications for dietary studies in the wild. Physiological and Biochemical Zoology 78: 106-115. doi:10.1086/425202

DENIRO, M.J. & EPSTEIN, S. 1981. Influence of diet on the distribution of carbon isotopes in animals. Geochimica et Cosmochimica Acta 42: 495-506. doi:10.1016/0016-7037(81)90244-1

FALXA, G. 1992. Prey choice and habitat use by foraging Black Oystercatchers: interactions between prey quality, habitat availability, and age of bird. PhD Thesis. Davis, USA: University of California, Davis.

FARMER, R.G. & LEONARD, M.L. 2011. Long-term feeding ecology of Great Black-backed Gulls (Larus marinus) in the northwest Atlantic: 110 years of feather isotope data. Canadian Journal of Zoology 89: 123-133. doi:10.1139/Z10-102

FRANCE, R.L. 1995. Carbon-13 enrichment in benthic compared to planktonic algae: foodweb implications. Marine Ecology Progress Series 124: 307-312. doi:10.3354/meps124307

FRANK, P.W. 1982. Effects of winter feeding on limpets by Black Oystercatchers Haematopus bachmani. Ecology 63: 1352-1362. doi:10.2307/1938863

GRUBER, N., KEELING, C.D., BACASTOW, R.B. ET AL. 1999. Spatiotemporal patterns of carbon-13 in the global surface oceans and the oceanic Suess effect. Global Biogeochemical Cycles 50 13: 307-335. doi:10.1029/1999GB900019

GUO, C., KONAR, B.H., GORMAN, K.B. ET AL. 2022. Environmental factors important to high-latitude nearshore estuarine fish community structure. Deep-Sea Research Part II: Topical Studies in Oceanography 201: 105109. doi:10.1016/j.dsr.2022.105109

HARAMIS, G.M., JORDE, D.G., MACKO, S.A. ET AL. 2001. Stable-isotope analysis of canvasback winter diet in upper Chesapeake Bay. The Auk 118: 1008-1117. doi:10.1642/0004-8038(2001)118[1008:SIAOCW]2.0.CO;2

HARLEY, C.D.G., HUGHES, A.R., HULTGREN, K.M. ET AL. 2006. The impacts of climate change in coastal marine systems. Ecology Letters 9: 228-241. doi:10.1111/j.1461-0248.2005.00871.x

HARTWICK, E.B. 1976. Foraging strategy of the Black Oystercatcher Haematopus bachmani Audubon. Canadian Journal of Zoology 54: 142-155. doi:10.1139/z76-015

HAZLITT, S.L., YDENBERG, R.C. & LANK, D.B. 2002. Territory structure, parental provisioning, and chick growth in the American Black Oystercatcher Haematopus bachmani. Ardea 90: 219-227.

HIPFNER, J.M. & ELNER, R.W. 2013. Sea-surface temperature affects breeding density of an avian rocky intertidal predator, the Black Oystercatcher Haematopus bachmani. Journal of Experimental Marine Biology and Ecology 440: 29-34. doi:10.1016/j.jembe.2012.11.007

HOBSON, K. & CLARK, R.G. 1992. Assessing avian diets using stable isotopes I: turnover of δ13C in tissues. The Condor 94: 181-188. doi:10.2307/1368807

HOBSON, K.A., SINCLAIR, E.H., YORK, A.E. ET AL. 2004. Retrospective isotopic analysis of stellar sea lion tooth annuli and seabird feathers: a cross-taxa approach to investigating regime and dietary shifts in the Gulf of Alaska. Marine Mammal Science 20: 621-638. doi:10.1111/j.1748-7692.2004.tb01183.x

IBANEZ, C.M., RIERA, R., LEITE, T. ET AL. 2021. Stomach content analysis in cephalopods: past research, current challenges, and future directions. Reviews in Fish Biology and Fisheries 31: 505-522. doi:10.1007/s11160-021-09653-z

INGER, R. & BEARHOP, S. 2008. Applications of stable isotope analysis to avian ecology. Ibis 150: 447-461. doi:10.1111/j.1474-919X.2008.00839.x

JENNINGS, S. & VAN DER MOLEN, J. 2015. Trophic levels of marine consumers from nitrogen stable isotope analysis: estimation and uncertainty. ICES Journal of Marine Science 72: 2289-2300. doi:10.1093/icesjms/fsv120

JOHNSON, M., CLARKSON, P., GOLDSTEIN, M.I. ET AL. 2010. Seasonal movements, winter range use, and migratory connectivity of the Black Oystercatcher. The Condor 112: 731-743. doi:10.1525/cond.2010.090215

KOHLER, S.A., CONNAN, M., HILL, J.M. ET AL. 2011. Geographic variation in the trophic ecology of an avian rocky shore predator, the African Black Oystercatcher, along the southern African coastline. Marine Ecology Progress Series 435: 235-249. doi:10.2307/24875477

LAROCHE, N.L, KING, S.L., ROGERS, M.C. ET AL. 2021. Behavioral observations and stable isotopes reveal high individual variation and little seasonal variation in sea otter diets in Southeastern Alaska. Marine Ecology Progress Series 677: 219-232. doi:10.3354/meps13871

LI, C.H., ROTH, J.D., & DETWILER, J.T. 2018. Isotopic turnover rates and diet-tissue discrimination depend on feeding habits of freshwater snails. PLoS ONE 13: e0199713. doi:10.1371/journal.pone.0199713

LINDBERG, D.R., WARHEIT, K.I. & ESTES, J.A. 1987. Prey preference and seasonal predation by Oystercatchers on limpets at San Nicolas Island, California, USA. Marine Ecology-Progress Series 39: 105-113. doi:10.3354/meps039105

MANRIQUEZ, P.H., JARA, M.E., GONZALEZ, C.P. ET AL. 2022. Multiple-stressor effects of ocean acidification, warming and predation risk on the early ontogeny of a rocky-shore keystone gastropod. Environmental Pollution 302: 118918. doi:10.1016/j.envpol.2022.118918

MARTEL, S.I., FERNANDEZ, C., LAGOS, N.A. ET AL. 2022. Acidification and high-temperature impacts on energetics and shell production of the edible clam Ameghinomya antiqua. Frontiers in Marine Science 9: 972135. doi:10.3389/fmars.2022.972135

MCFARLAND, B.A. & KONAR, B. 2010. Physical and biological habitat preferences of Black Oystercher breeding territories in Kenai Fjords National Park. Natural Resource Technical Report NPS/SWAN/NRTR—2010/410. Fort Collins, USA: National Park Service.

MCGOWAN, C.P. & SIMONS, T.R. 2005. A method for trapping breeding adult American Oystercatchers. Journal of Field Ornithology 76:46-49. doi:10.1648/0273-8570-76.1.46

MILLER, M.W.C., LOVVORN, J.R., GRAFF, N.R., STELLRECHT, N.C. 2022. Use of marine v. freshwater proteins for egg-laying and incubation by sea ducks breeding in Arctic tundra. Ecosphere 13: e4138. doi:10.1002/ecs2.4138

MINAGAWA, M. & WADA, E. 1984. Stepwise enrichment of 15N along food chains: further evidence and the relation between δ13N and animal age. Geochimica et Cosmochimica Acta 48: 1135-1140. doi:10.1016/0016-7037(84)90204-7

MIZUTANI, H., FUKUDA, N. & KABAYA, Y. 1992. (13)C and (15)N enrichment factors of feathers of 11 species of adult birds. Ecology 73: 1391-1395. doi:10.2307/1940684

MORSE, J.A., POWELL, A.N. & TETREAU, M.D. 2006. Productivity of Black Oystercatchers: effects of recreational disturbance in a national park. The Condor 108: 623-633. doi:10.1650/0010-5422(2006)108[623:POBOEO]2.0.CO;2

OGDEN, L.J.E., HOBSON, K.A. & LANK, D.B. 2004. Blood isotopic (δ13C and δ13N) turnover and diet-tissue fractionation factors in captive Dunlin (Calidris alpina pacifica). The Auk 121: 170-177. doi:10.1642/0004-8038(2004)121[0170:BICANT]2.0.CO;2

ORING, L.W., ABLE, K.P., ANDERSON, D.W. ET AL. 1998. Guidelines for the use of wild birds in research. The Auk 115 (Supplement): 1A-44A.

OWEN, J. 2011. Collecting, processing, and storing avian blood: a review. Journal of Field Ornithology 82: 339-354. doi:10.1111/j.1557-9263.2011.00338.x

PARNELL, A.C., INGER, R., BEARHOP, S. & JACKSON, A.L. 2010. Source partitioning using stable isotopes; coping with too much variation.: PLoS ONE 5: e9672. doi:10.1371/journal.pone.0009672

PEARSON, S.F., LEVEY, D.J., GREENBERG, C.H., DEL RIO, C.M. 2003. Effects of elemental composition on the incorporation of dietary nitrogen and carbon isotopic values in an omnivorous songbird. Oecologia 135: 516-523. doi:10.1007/s00442-003-1221-8

POE, A.J., GOLDSTEIN, M.I., BROWN, B.A. & ANDRES, B.A. 2009. Black Oystercatchers and campsites in Western Prince William Sound, Alaska. Waterbirds 32: 423-429. doi:10.1675/063.032.0307

POST, D.M. 2002. Using stable isotopes to estimate trophic position: models, methods, and assumptions. Ecology 83: 703-718. doi:10.1890/0012-9658(2002)083[0703:USITET]2.0.CO;2

ROBINSON, B.H., COLETTI, H.A., PHILLIPS, L.M. & POWELL, A.N. 2018. Are prey remains accurate indicators of chick diet? A comparison of diet quantification techniques for Black Oystercatchers. Wader Study 125: 20-32. doi:10.18194/ws.00105

ROBINSON, B.H., PHILLIPS, L.M. & POWELL, A.N. 2019. Energy intake rate influences survival of Black Oystercatchers Haematopus bachmani broods. Marine Ornithology 47: 277-283.

ROGERS, L.A., WILSON, M.T., DUFFY-ANDERSON, J.T. ET AL. 2021. Pollack and “the Blob”: Impacts of a marine heatwave on walleye pollack early life stages. Fisheries Oceanography 30: 142-158. doi:10.1111/fog.12508

ROGERS, M.C., PEACOCK, E.L., SIMAC, K., O'DELL, M.B. & WELKER, J.M. 2015. Diet of female polar bears in the southern Beaufort Sea: evidence for an emerging alternative foraging strategy in response to environmental change. Polar Biology 38: 1035-1047. doi:10.1007/s00300-015-1665-4

STANEK, A.E., WOLF, N., HILDERBRAND, G.V. ET AL. 2017. Variation in seasonal foraging strategies in Alaska gray wolves in a salmon subsidized ecosystem. Canadian Journal of Zoology 95: 555-563. doi:10.1139/cjz-2016-0203

TESSLER, D.F., JOHNSON, J.A., ANDRES, B.A., THOMAS, S. & LANCTOT, R.B. 2014. A global assessment of the conservation status of the Black Oystercatcher Haematopus bachmani. International Wader Studies 20: 83-96.

THERRIEN, J.-F., FITZGERALD, G., GAUTHIER, G. & BETY, J. 2011. Diet-tissue discrimination factors of carbon and nitrogen stable isotopes in blood of Snowy Owl (Bubo scandiacus). Canadian Journal of Zoology 89: 343-347. doi:10.1139/z11-008

WATANABE, Y.W., CHIBA, T. & TANAKA, T. 2011. Recent change in the oceanic uptake rate of anthropogenic carbon in the North Pacific subpolar region determined by using a carbon-13 time series. Journal of Geophysical Research 116: C02006. doi:10.1029/2010JC00619

YANG, Q., COKELET, E.D., STABENO, P.J. ET AL. 2019. How “The Blob” affected groundfish distributions in the Gulf of Alaska. Fisheries Oceanography 28: 434-453. doi:10.1111/fog.12422

Search by author or title:

Browse previous volumes: