This is part of a culmination of a 10 year collaborative effort involving many state agencies, academic institutions and NGOs. This 612 page atlas, based on the fieldwork of 2000 birdwatchers, provides details on the status and distribution of the Commonwealth’s 190 breeding bird species.
Wilson, Andrew M. “Analytical Methods.” Second Atlas of Breeding Birds in Pennsylvania. Andrew M. Wilson, Daniel W. Brauning and Robert S. Mulvihill, Eds. University Park, PA: Penn State Press, 2012. 38-47.