Journal or Book Title
North American Birds
The fall migration marks a transition between the breeding and non-breeding seasons. While some species, such as Mourning Dove, are still reproductively active well into autumn, most species that breed north of Mexico and the Caribbean have completed their primary breeding period, and those that migrate are making their way to wintering areas. The sojourn to nonbreeding sites includes some epic migrations, some of which are still being discovered--for example, the 11,000-km presumably non-stop flight of baueri Bar-tailed Godwits from coastal Alaska to New Zealand. Most species have much shorter flights, usually broken into segments, and other species reside in the same area year-round or make only facultative movements.
American Birding Association
Dinsmore, Stephen J. and Farnsworth, Andrew, "Changing Seasons: Weatherbirds" (2006). Natural Resource Ecology and Management Publications. 44.