Smithsonian Environmental Research Center (SERC)
P. O. Box 28
Edgewater, Maryland 21037

phone: 443.482.2224

fax: 443.482.2370

Seasonal interactions and the relevance of understanding migratory connectivity.

 

Peter P. Marra, Smithsonian Environmental Research Center, PO Box 28, Edgewater, MD, USA 21037-0028; E-mail: marrap@si.edu.

Mike Webster, School of Biological Sciences ; Washington State University, PO Box 644236 ; Pullman , WA USA 99164-4236; E-mail: mwebster@wsu.edu

Austral migrants breed during the southern summer in south temperate South America , and migrate north for remainder of the year to a distant and ecologically different location. The conditions and selective pressures at the winter location are likely to affect individual performance during the breeding season, and vice versa. This simple fact has important implications for the ecology, evolution, and conservation of migratory birds. Such inter-seasonal effects are poorly understood within all bird migration systems, in large part because it has been difficult to determine the connections between specific summer and winter populations.

A better understanding of migratory connectivity will allow researchers to follow populations or individuals throughout the annual cycle and thereby address questions regarding the ecological and evolutionary implications of seasonal interactions. We offer a brief review of the advances in genetic analyses, and stable isotope chemistry that now make it possible to determine the population origin of individual birds. In addition, we present examples to illustrate the importance of understanding migratory connectivity. Finally, we urge researchers studying austral migrants to pull feathers (i.e., 2 tail and 3-4 breast) from captured birds. These partial specimens can act as both vouchers for positive species identification and to provide valuable genetic and isotopic information as a marker of origin.