This map provides our best guess of population change for the species over its range. Areas of increase are blue, and areas of decline are red. Areas where there is no apparent trend, or where we do not have enough information to say that a trend exists, are also indicated. Note that these maps are designed to provide a general view of population change for the long-term. Because they are based on averages of trend estimate for each route, they do not provide much insight into short-term changes within the BBS period. To get trend estimates for a specific region or time, please use the trend estimation parts of the Home Page.
Also, remember that the BBS did not begin in the Western United States and most of southern Canada until 1968, and in the Central United States in 1967, so trends do not always provide information from the first years of the survey.