We report forest bird population trends from 1987–2005 at a 280.7-ha site in Chester, MA. Our study site consisted primarily of mid-successional (70–90 yr old) forest in a landscape of similar, non-fragmented forest. Using point counts at 100 stations, we detected 94 species in early June over all years. Mean numbers of species and detections/yr were 57 and 1104, respectively. Species richness and total detections were stable (P ≤ 0.05). We analyzed trends for the 36 most frequently detected species. Four species exhibited significant increasing trends and 10 significant declining trends; 22 species were stable or exhibited no significant trend (P ≤ 0.05). Whether a species was a resident, short-distance, migrant, or Neotropical migrant did not appear to be a determinative factor for trends. Trends were more readily explained by (I) areal and structural expansion of mature forest conditions and (II) forestry treatments that affected 70 ha (25%) of the study site. We report few changes in species abundances that could not be plausibly explained by intra-site habitat changes and no mysterious or alarming changes in the first 19 years of this study.