Figure 2. Abundance of avian breeding species and those species affected by window collisions.

Maximum abundance of live birds observed during point counts and number of carcasses (adults, juvenile, or could not be aged) resulting from window collisions in northwestern Illinois, USA, in two summer breeding seasons: (A) 2009 and (B) 2010. Species with maximum abundances of zero for a given year were not considered as being part of the breeding community for that year.