9704253 Desmond The International Research Fellow Awards Program enables U.S. scientists and engineers to conduct three to twenty four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twenty-four-month postdoctoral research visit by Dr. Martha J. Desmond to work with Professor Alberto Lafon Terrazas at the Universidad Autonoma de Chihuahua in Chihuahua, Mexico. The U.S.-Mexico Program will provide 50% of the funding for this project. Desmond proposes to examine populations and community assemblages of grassland birds on wintering ground in Northern Mexico. She will look at data on life-history characteristics which are unknown for many grassland birds in winter habitats. This is essential to understand how these migrants are adapted to use habitats. She will test hypotheses related to differential migration due to morphological size variation between sexes and inter-sexual and age class competition for resources. Many of these species are showing significant population declines. This research will specifically examine the influence grazing by domestic and native herbivores on habitat use by grassland- adapted birds and test hypotheses related to habitat use and community structure. Information on the basic life history characteristics on winter grounds is essential for understanding community dynamics and evaluating potential threats to these populations. ***
