Our Liviiiii Rcsdidxex — Binis 



49 



Sowls. A.L.. A.R. DeGange. J.W. Nelson, and G.S. Lester. 



1980. Catalog of California seabird colonies. U.S. Fish 



and Wildlife Service, FWS/OBS .^7/80. 371 pp. 

 Speich. S.M., and T.R. Wahl. 1989. Catalog of Washington 



seabird colonies. U.S. Fish and Wildlife Service. 



Biological Rep. 88(fi). ."ilO pp. 

 Takekaw^i. J.E., H.R. Carter, and TE. Harvey. 199(1. Decline 



of the common murre in central California, 198U-1986. 



Pages 149-163 in S.G. Sealy. ed. Auks at sea. 



Proceedings of an International Symposium of the 



Pacific Seabird Group. Studies in Avian Biology 14. 

 Varoujean. D.H.. and R.L. Pitman. 1979. Oregon seabird 



survey 1979. U.S. Fish and Wildlife Service, Portland, 



OR. Unpublished report. 



Vermeer, K.. K.T. Briggs, K.H. Morgan, and D. Siegel- 

 Causey, eds. 1993. The status, ecology, and conservation 

 of marine birds of the North Pacific. Proceedings of a 

 Pacific Seabird Group Symposium. Canadian Wildlife 

 Service Spec. Publ. Ottawa. Ontario. 263 pp. 



Wilson, U.W. 1991. Responses of three seabird species to Fl 

 Nino events and other wami episodes on the Washington 

 coast, 1979-1990, Condor 93:S.'i3-8.S8. 



Wilson, U.W., and D.A. Manuwal. 1986. Breeding biology 

 of the rhinoceros auklet m Washington. Condor 88:143- 



For further information: 



Harry R, Carter 



National Biological Service 



California Pacific Science Center 



6924 Tremont Rd. 



Di.\on. CA 95620 



Abiuit 100 million seabirds reside in marine 

 walei'.s of Alaska during some pail ol' the 

 year. Perhaps half this population is eomposed 

 of 50 species of nonbreeding residents, visitors, 

 and breeding species that use marine habitats 

 only seasonally (Gould et al. 1982). Another 30 

 species include 40-60 million individuals that 

 breed in Alaska and spend most of their lives in 

 U.S. ten-itorial waters (Sowls et al. 1978). 

 Alaskan populations account for more than 

 95% of the breeding seabirds in the continental 

 United States, and eight species nest nowhere 

 else in North Amenca"(USFWS 1992). 



Seabird nest sites include rock ledges, open 

 ground, underground bunows. and crevices in 

 cliffs or talus. Seabirds take a variety of prey 

 from the ocean, including krill. small fish, and 

 squid. Suitable nest sites and oceanic prey are 

 the most important factors controlling the natur- 

 al distribution and abundance of seabirds. 



The impetus for seabird monitoring is based 

 partly on public concern for the welfare of these 

 birds, which are affected by a variety of human 

 activities like oil pollution and commercial fish- 

 ing. Equally important is the role seabirds serve 

 as indicators of ecological change in the marine 

 environment. Seabirds are long-lived and slow to 

 mature, so parameters such as breeding success, 

 diet, or survival rates often give earlier signals of 

 changing environmental conditions than popula- 

 tion size itself. Seabird survival data are of inter- 

 est because they reflect conditions affecting 

 seabirds in the nonbreeding season, when most 

 annual mortality occurs (Hatch et al. 1993b). 



Techniques for monitoring seabird popula- 

 tions vary according to habitat types and the 

 breeding behavior of individual species (Hatch 

 and Hatch 1978, 1989; Byrd et al. 1983). An 

 affordable monitoring program can include but 

 a few of the 1.300 seabird colonies identified in 

 Alaska, and since the mid-1970"s, monitoring 

 efforts have emphasized a small selection of 

 surface-feeding and diving species, primarily 

 kittiwakes (Rissa spp.) and murres {Uria spp.). 

 Little or no information on trends is available 

 for other seabirds (Hatch 1993a). The existing 



monitoring program occurs largely on sites 

 within the Alaska Maritime National Wildlife 

 Refuge, which was established primarily for the 

 conservation of marine birds. Data are collected 

 by refuge staff, other state and federal agencies, 

 private organizations, university faculty, and 

 students. 



Status of Monitored Birds 



Kittiwakes 



Kittiwakes are small, pelagic (open sea) 

 gulls that range widely at sea and feed on a vari- 

 ety of small fish and plankton, which they cap- 

 ture at the sea surface. Black-legged kittiwakes 

 {RIssd tri(lactyla) have been studied intensively 

 because they are widely distributed and easy to 

 observe. Among 10 locations for which popula- 

 tion trend data are available, 3 show significant 

 declines since the mid-1970"s, 3 show increas- 

 es, and 4 show no consistent trends (Fig. 1 ). The 

 overall trend is unknown, although widespread 

 declines are anticipated because of a downward 



Seabirds in 

 Alaska 



by 



Scott A Hatch 



John F. Piatt 



National Biological Senice 



Dense colonic >! . 



Islands, western Gulf of Alaska. 



Ml iiuirres (Uriel cicilf;c) breed on bare cliff ledges — here on the Semidi 



