Documentation for BBS 50-stop data 1966-1996.pdf

From the dataset abstract

The Breeding Bird Survey (BBS) is a standardized and one of the rare long-term databases of ecological communities. The BBS permits us to understand long-term changes in North American...

Source: The North American Breeding Bird Survey (BBS) is a large-scale, long-term monitoring program designed to track the status and trends of North American bird populations.