MSA: Macro-Demography of North America's Migratory Avifauna

Cornell University, Ithaca NY

Investigators

Abstract

Reversing the global loss of biodiversity is a primary challenge of our time, however the reasons for species declines are often poorly understood. Birds exemplify this crisis, with the North American continent supporting 3 billion fewer birds today than in 1970. Migratory birds are particularly hard hit. These birds travel vast distances between their wintering and breeding grounds, making it difficult to pinpoint where threats exist and where conservation efforts should be focused. To understand current bird declines, researchers require accurate estimates of the birth and death rates of birds across the vast geographic areas they visit. However, such information is currently only available for a few select locations during short periods of the year. This research will address these challenges by developing novel tools to measure the birth and death rates of birds across an entire continent and throughout the whole year. The insights generated by these efforts will help researchers to understand which factors have been causing population declines. In particular, researchers will investigate how extreme climatic events such as heat waves and cold spells have affected birth and death rates. Explaining such year-to-year changes in bird populations sizes will be a critical step towards understanding long-term bird declines. By gaining insight into how to halt ongoing bird losses, this work aims to sustain the vital ecological, economic, and social services that birds provide to humans and the environment. To create their new analyses, researchers will rely on three novel ‘big data’ resources to track bird populations throughout the year. First, the US weather radar network (NEXRAD) will be used to study the flow of migrants into and out of North America during fall and spring migration. Comparing these numbers between adjacent seasons will enable researchers to estimate the birth and death rates of all migratory birds combined. Second, observations from hundreds of thousands of volunteer citizen scientists (eBird data) and dynamic species distribution models will be used to track seasonal variation in the numbers of birds recorded. This resource will capture species-specific patterns that are not available from the radar data. Third, remote sensing data and the National Ecological Observatory Network (NEON) will be used to understand temperature and phenological extremes, which will be explored as a mechanism driving population changes. Overall, this research aims to develop the tools to understand current population declines and point towards a road map for the recovery and conservation of the mass migration of birds. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.