Species at Risk Proposal: Dramatic population declines in the Kittlitzs murrelet: assessing the magnitude and potential causes of the decline

Piatt, John

The Kittlitz's murrelet (Brachyramphus brevirostris) is a rare seabird that nests in alpine terrain and generally forages near tidewater glaciers during the breeding season. Because nest sites are inaccessible and at-sea behavior is difficult to study, very little is known about the natural history and ecology of this species. More than 95% of the global population breeds in Alaska, with the remainder occurring in the Russian Far East. A global population estimate using best-available data in the early 1990s was 20,000 individuals. However, survey data from two core areas (Prince William Sound and Glacier Bay) show 80-90% population declines during the past 10-20 years. In response to these declines, a coalition of environmental groups petitioned the USFWS in May of 2001 to list the Kittlitz's murrelet under the Endangered Species Act. Because so little is known about the biology of the species, both the causes and true magnitude of this decline are unknown. Leading hypotheses explaining all or part of the decline include naturally occurring changes in food abundance, glacial recession, oil spill mortality, vessel disturbance in foraging areas, and gillnet mortality. Effective management of the species is currently impossible because of the lack of basic information about its status and ecology. We propose to address critical information needs in a multi-year study that examines (1) status of Kittlitz's murrelets in areas where distribution and abundance are poorly known, (2) Kittlitz's murrelet ecology and habitat relationships in Glacier Bay, (3) the impact of vessel traffic on foraging Kittlitz's murrelets in Glacier Bay, and (4) retrospective analysis of historical data collected ancillary to other work, focusing on diet, distribution, population trends, genetic population structure, and breeding biology. The proposed work addresses logistically difficult research questions in a cost-effective manner by building on base funding from the National Park Service for work in Glacier Bay, and by analyzing and disseminating information from historical data and archival specimens that have been opportunistically collected by a variety of researchers.