Abstracts
SEARCH Open Science Meeting
October 27, 2003
Seattle, Washington, USA
Multi-Decadal Response of a Seabird to the Arctic Oscillation
George Divoky1
1Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA, Phone 206-365-6009, fngjd@uaf.edu
Unlike the abundant evidence of biota responding to lower latitude atmospheric oscillations, the Arctic Oscillation's (AO) effect on biological populations is sparse, primarily due to the paucity of long-term studies in the region. A population of Black Guillemots, an arctic seabird resident in the Arctic for the entire year, was monitored near Point Barrow from 1975-2002 and found to show phenological and demographic sensitivity to the winter AO. While major changes were associated with the 1989 shift from a cold to warm phase AO, the population also demonstrated sensitivity to interannual AO variation throughout the study. A positive winter AO was associated with an earlier spring snowmelt that facilitated access to nesting cavities and allowed earlier egg laying. The majority of annual variation in timing of egg laying was explained by the previous winter AO, occurring 12 months earlier, revealing a previously unreported lag in local cryospheric response. The positive winter AO in the 1990s was also correlated with an almost 50 percent decline in the breeding population, apparently due to the accelerated melting of pack ice, the preferred guillemot foraging habitat in all seasons.
Abstract Categories: Biological Feedbacks
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