Migratory songbird species have shown some of the largest declines across the animal kingdom. Reasons for these declines are difficult to pinpoint. Complexities of their annual cycle—particularly those related to migration and the use of multiple habitats across continents—make it difficult to determine where a population could be experiencing problems such as habitat loss or shortage of food supplies. Basic information about migratory processes and patterns, combined with songbird natural history is critical to our understanding of how environmental changes impact these species.
Wyoming's upper Hoback River Vallley offers a unique opportunity for BRI researchers to study local fauna. This work provides an integrated wildlife research and conservation plan for the valley, including habitat enhancement to improve the use of key wildlife species and subsequent viewing opportunities for visitors.
In 2011, BRI began monitoring efforts at the River Point Conservation Area in Falmouth, Maine, with an emphasis on tracking bird populations. Migration monitoring occurs in both spring and fall. In the summer, research efforts focus on the Veery and Tree Swallow.
Ever since BRI biologists discovered the threats mercury can pose to songbird populations, we have stressed the need to better understand the exposure of mercury in songbirds across North America south into Central America. Efforts to determine the effects of mercury on songbird reproductive success have emphasized the Carolina Wren, which resulted in an important publication on the topic. More investigations are planned in Latin America to better understand the impacts of mercury on neotropical migrants and tropical resident birds.
The changing technology of transmitter devices for following wildlife has resulted in new abilities to track smaller birds, like songbirds. BRI is conducting movement studies using geolocator devices in both Maine and Massachusetts. More work is planned in the future.