A Special Avian Seminar
Peter P. Marra, PhD, Director, Smithsonian Migratory Bird Center, National Zoological Park, Washington, D.C. will present, "Studying birds in the context of the annual cycle: Carry-over effects and seasonal interactions."
Migratory birds spend different parts of the annual cycle in geographically disparate places. The conditions and selective pressures during each period are likely to affect individual performance during subsequent periods. This simple fact presents us with considerable obstacles for understanding how agents of global change (i.e., climate, land-use) will influence the ecology, evolution, and conservation of migratory birds. Such inter-seasonal effects are poorly understood within most avian migration systems, in large part because it has been difficult to follow individuals and specific populations year round (i.e., migratory connectivity). In addition, for most species there exists an extreme research bias towards breeding rather than non-breeding season biology. Furthermore, the limiting factors and regulatory mechanisms that determine abundance remain poorly understood for most bird species. Here, I will show using long-term research on several species from throughout their annual cycle how events on wintering grounds acting on individuals, as well as density–dependent survival have important consequences for breeding events and annual survival. Understanding how global change will influence migratory organisms requires the study of biological phenomena in the context of the entire annual cycle.