Southern Sonora contains large saltwater estuaries that are important wintering and migratory habitats for many species of shorebirds, waterfowl, seabirds, and colonial waterbirds. There are very few data available concerning wintering aquatic bird populations. Increased monitoring will help inform management and conservation planning for this important region. This project will provide data for over 86 species of birds, 38 of which are species of concern in the Sonoran Joint Venture Conservation Plan. This project will also train regional field biologists from throughout northwest Mexico in monitoring methods for aquatic birds, as well as share data and results with all interested stakeholders.