Consequences of migratory behavior in the ecology and biogeographical distribution of birds

Migratory birds, because of their ability to fly long distances and establish wintering and breeding populations in two different regions are considered highly successful colonists. In the present study, I assessed if migration has enhanced the ability of birds to colonize new regions. I used a comparative approach, to determine the association between migratory behavior and biogeographic distribution of birds along continents and oceanic islands. To determine if migration has affected the way species interact with their environment, I compared the patterns of abundance and distribution of migrant and resident birds in a large region of western Mexico.; I determined whether the shape and size of the geographic range in birds of the northern hemisphere (e.g. Europe and North America) was associated with migratory behavior. Additionally, I compared the geographic distribution of birds against non-flying mammals of the northern hemisphere to assess the consequences of flight in the colonization capabilities of terrestrial vertebrates. The distribution of birds and mammals was related to the ability to fly, with birds having a more widespread distribution than mammals. Long-distance migrant distributions were confined to either the western or eastern hemisphere. Long-distance migrant birds had a vertical distribution along a north-south axis that reflects the migratory route between their breeding and wintering grounds.; I studied bird colonization and dispersal events in oceanic islands of the world and the introduction of birds species in the Hawaiian Islands in relation to the migratory distance of birds at three different taxonomic levels (species, genera, and families). A quantile regression analysis determined that the ability to colonize distant islands decreased with migratory distance. Whereas accidental sightings of long-distance migrants increased on islands distant from the mainland. Among several traits, migratory behavior and taxonomic classification were the best predictors of success or failure of introductions in the Hawaiian Islands. The results supported the hypothesis that the direction and extent of colonization in migratory birds is limited by the physiological and behavioral control of their migratory behavior.; I tested whether the adaptations to save energy (e.g. pointed wings) and those that determine the timing, direction, and distance of migratory movement (e.g. Zugurunhe) have constrained the ecology of migrant birds. I performed a comparative study of the habitat and vegetation structure used by residents, short-distance, and long-distance migrant birds of varying taxonomic relatedness in western Mexico. A two way ANOVA demonstrated a small relationship between migratory status and habitat use in distantly related taxa. Whereas permutation tests showed no relationship between migratory status and mean vegetation structure used. The results suggested that the specialized adaptations of migratory behavior do not result in large differences in the ecology of migrant and resident birds. (Abstract shortened by UMI.)...