Background/Question/Methods: Jointly coordinated by the U.S. Geological Survey and the Canadian Wildlife Service, the North American Breeding Bird Survey is the primary source of long-term, large-scale population data for over 400 of North America’s breeding bird species.  At a cost of roughly $900 per species, the program is regarded as a model for efficient large scale monitoring efforts.  The success of the BBS stems from three major components: a scientifically rigorous sampling design, a straight forward field protocol, and an extensive volunteer participant base.  Here we combine the results of two BBS participant surveys with queries from the four-million record BBS database to 1) develop a profile of BBS volunteers, 2) examine BBS participant demographics and 3) examine the relationship between BBS management activities and long term participation trends.  
Results/Conclusions: More than 8600 individuals have participated in the BBS in its 40 year existence with approximately 2000 volunteering annually since the 1990s.  Volunteer retention is high with 75% of new recruits returning the following year and remaining with the program, on average, for 8 years.  Despite the program’s success in attracting highly motivated and well trained volunteers, BBS volunteer trends exhibit a number of gains and plateaus which are further discussed.