Many species migrate, using habitats in different locations during different parts of the year. Many bird species, for example, breed during the summer months at higher latitudes and spend winters at lower latitudes. Modeling the dynamics of migratory species is complicated by the fact that growth, survival, and reproduction may be very different in each location, and existing population models are not well suited for migratory species. This project will develop models based on graph theory that are appropriate for migratory species, and then use data for Tree Swallows (Tachycineta bicolor) to parameterize those models. Stable isotopes of hydrogen and strontium, measured in feathers of birds collected in their winter habitats, will be matched against maps of isotope abundances across North America, providing information about where individual birds lived during the summer breeding season. Broader impacts of this project will include training of undergraduate and graduate students, and development of models that may inform conservation planning efforts for migratory species.
