After reviewing the history of monitoring in North America, I discuss the origin of the Breeding Bird Survey (BBS), including the need for such a program and field testing of methodology to determine optimum starting time, length of stop, number of stops per route, and acceptable weather conditions. Before initiating the survey I ran sample routes in Maryland, New Hampshire, South Dakota, Colorado, and Alaska to become familiar with environmental factors affecting roadside counts. I also ran the same route multiple times throughout a season to measure progressive changes in detectability, and did simultaneous double sampling to study observer effects. The BBS was field-tested with 50 routes throughout Maryland and ten in Delaware in 1965, then launched in the states and provinces east of the Mississippi River in 1966, and in the rest of the continent in 1967 and 1968. For quality control, all participants in 1965 were required, in addition to their assigned 50-stop route, to also run a 50-stop route that I had run the same year. In the first few years the results were keypunched into cards, and the cards were sorted various ways to prepare summaries. The electronics age has completely changed input and analysis procedures and ways of displaying results, but the field procedures are still the same as forty years ago. Thoughts on improving the BBS are shared.
Additional Publication Details
Reflections on 40 years of Breeding Bird Survey
Wilson Ornithological Society and Association of Field Ornithologists Joint Meeting, April 21-24, Beltsville, Maryland. Abstracts