The North American Breeding Bird Survey
From their website: The North American Breeding Bird Survey (BBS) is a long-term, large-scale, international avian monitoring program initiated in 1966 to track the status and trends of North American bird populations. The USGS (United States Geologic Survey at usgs.gov) Eastern Ecological Science Center and Environment Canada’s Canadian Wildlife Service jointly coordinate the BBS program. More from the website: […]