The non-breeding ecology of a neotropical migratory songbird: The influence of habitat quality on spatial and social behavior and consequences for individual performance

Using radio-telemetry I examined the relationships among space use strategies and home range attributes along with behavioral and physical characteristics of the northern waterthrush (Seiurus noveboracensis). Evidence for territoriality emerged with the pattern that more aggressive individuals were more site-persistent and maintained more exclusive home ranges. A significantly greater proportion of these aggressive individuals were male. Territoriality had benefits, with birds occupying the most exclusive areas gaining mass during the study period. These benefits may be the result of maintaining higher-quality territories which were both wetter and had higher food availability than less exclusive home ranges. The probability of site-persistence was influenced by food availability. Birds that were not site-persistent consistently moved from drier areas with lower food availability to wetter areas with higher food availability. This mid--season movement does not appear o adequately compensate for initially lower levels of food availability as these birds tended to lose mass throughout the study period. Regardless of diurnal space use strategies, most birds were site-faithful to coastal red mangrove roost sites at night. Overall my results suggest that high-quality habitat, determined by moisture levels and food availability may be limiting for northern waterthrush. Continued habitat destruction and predictions of a drying climate on wintering areas have the potential to severely impact populations of this species.