Drivers of Stability in Declining Bird Communities in North America

Biodiversity loss is accelerating at an unprecedented rate and fundamentally altering the structure of ecological communities. Understanding how biodiversity loss affects the stability of communities, identifying the factors that promote ecosystem stability, and identifying how those factors change over time, is critical for understanding the trajectory of declining ecological communities and the ecosystem functions they support. Arguably the best documented example of biodiversity loss is the loss of nearly three billion North American birds in the past half century, a reduction of almost 30%. In our work, we seek to partition the stability of a North American bird community into its drivers in order to understand how stability is structured, and how that structure is changing. To do this, we will analyze long-term, avian population surveys across the United States and Canada to assess how stability is typically structured, how this structure varies across space and time, and what factors drive these patterns. Our preliminary analyses indicate that species richness is by far the largest contributor to community stability, and despite dramatic community declines, the fundamental mechanisms of stability remain intact, emphasizing the irreplaceable role of biodiversity in buffering ecosystems against collapse. Our work will result in a scientific paper and a policy brief for leading agencies and NGOs in bird conservation, including the U.S. Fish and Wildlife Service, American Bird Conservancy, National Audubon Society, and The Nature Conservancy.