| Summary: | Arctic environments have been profoundly affected by global climate change, and changes in tundra habitats, including changes in snow conditions, climatic variability and habitat types are predicted to have major impacts on the biodiversity and distribution of arctic biota. One likely impact of climatic change will be a decoupling of biological interactions among organisms at different trophic levels, leading to a 'phenological mismatch' in the seasonal timing of life-history events for plants, insects, birds and higher-level predators. Arctic breeding shorebirds are expected to be 'integrative sentinels' for the effects of global climate change because high energetic requirements, long-distance migratory movements, and synchronized timing of seasonal activities increase their vulnerability to changing environments. This project will examine the effects of environmental conditions in the Arctic on the ecology and trophic relationships of two species of migratory shorebirds: Semipalmated Sandpipers (Calidris pusilla) and Western Sandpipers (C. mauri). One challenge for assessing the ecological consequences of climate change is a lack of baseline data for most organisms. A unique feature of this project is that the researcher collected detailed data on the seasonal timing, demography and movements of sandpipers in a 4-year period (1993-1996) at an undisturbed 4 square km coastal tundra study site near Nome, Alaska. In this 3-year field project (2011-2013) the research team will monitor shorebird populations and four key environmental factors: climatic conditions, arthropod emergence, abundance of small mammals and predators. They will also deploy geolocator tags to determine migration routes and nonbreeding sites for the study populations. Data on shorebird ecology will be collected using standardized field protocols at the same site, under the direction of the lead investigator who collected the original data, and will span a 15-20 year interval of environmental change. The broader context of our research will be the comprehensive knowledge of the annual cycle of migratory sandpipers that has been developed under the 16-year research program of the 'Western Sandpiper Research Network'. This is one of the first field studies to test predictions of the 'phenological mismatch' hypothesis for arctic-breeding shorebirds and to examine long-term changes in trophic interactions among food resources, migratory sandpipers, and their predators. The hypothesis will be rejected if long-term changes are lacking but standardized sampling will provide a framework for future studies of ecological resilience. The hypothesis will be supported if warming climatic conditions have changed the timing of insect emergence without changes in phenology of shorebird nesting, potentially leading to declines in densities of nesting birds. Strong inferences about the effects of arctic conditions can be made because the study species breed sympatrically but have different migration routes and nonbreeding areas. This project will provide insights for conservation of migratory birds that breed at high latitudes in the Arctic. Traditional methods for surveying arctic birds are based on nest monitoring and this project will evaluate the extent to which more intensive demographic approaches are a useful alternative. The project will offer training opportunities for one PhD student and up to six undergraduate students. Outreach in the community of Nome, Alaska will include annual meetings with native stakeholders, interviews with journalists, and preparation of public display media for the Nome visitor center.
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