Movements of Bird Population
Every year birds are reported in unusual locations and sometimes in unusual numbers. Questions revolve around such considerations as range expansion, irruptive behavior, or changes in migration patterns. Some answers can be obtained by gathering observations from individual bird-watchers all over the continent and examining maps of the distrbutions using Geographical Information Systems (GIS). This approach is the basis of the BirdSource web site, managed by the Cornell Lab of Ornithology and the National Audubon Society.
Using data from BirdSource, bird population movements are mapped and presented on this section of the BirdSource web site.