MEPS 357:301-311 (2008)  -  DOI: https://doi.org/10.3354/meps07325

Seasonal and distributional patterns of seabirds along the Aleutian Archipelago

Martin Renner1,*, George L. Hunt Jr.1, John F. Piatt2, G. Vernon Byrd3

1School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, Washington 98195, USA
2Alaska Science Center, U. S. Geological Survey, 1011 E. Tudor Rd, Anchorage, Alaska 99503, USA
3Alaska Maritime National Wildlife Refuge, 95 Sterling Highway, Suite 1, Homer, Alaska 99603, USA

ABSTRACT: The Aleutian Archipelago is of global importance to seabirds during the northern summer, but little is known about seabird use of these waters during winter. We compare summer and winter abundances of seabirds around 3 islands: Buldir in the western, Kasatochi in the central, and Aiktak in the eastern Aleutians. The density of combined seabird biomass in nearshore marine waters was higher in summer than in winter at Buldir and Kasatochi, but was higher in winter at Aiktak, despite the departure of abundant migratory species. Comparing foraging guilds, we found that only piscivores increased at the western and central sites in winter, whereas at the eastern site several planktivorous species increased as well. The only planktivore remaining in winter at the central and western sites in densities comparable to summer densities was whiskered auklet Aethia pygmaea. Crested auklet Aethia cristatella and thick-billed murre Uria lomvia showed the greatest proportional winter increase at the eastern site. The seasonal patterns of the seabird communities suggest a winter breakdown of the copepod-based food web in the central and western parts of the archipelago, and a system that remains rich in euphausiids in the eastern Aleutians. We suggest that in winter crested auklets take the trophic role that short-tailed shearwaters Puffinus tenuirostris occupy during summer. We hypothesize that advection of euphausiids in the Aleutian North Slope Current is important for supporting the high biomass of planktivores that occupy the Unimak Pass region on a year-round basis.


KEY WORDS: Aleutian North Slope Current · Euphausiids · Indicator species · Seabird biomass


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Cite this article as: Renner M, Hunt GL Jr, Piatt JF, Vernon Byrd G (2008) Seasonal and distributional patterns of seabirds along the Aleutian Archipelago. Mar Ecol Prog Ser 357:301-311. https://doi.org/10.3354/meps07325

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