Code and Supporting Files for reproducing quantitative analyses and figures in Levy et al., Increased bird abundances over 30 years in an extensive commercial forest landscape

Habitat loss and degradation are considered the primary drivers of continental bird declines. We replicated an extensive study of forest bird populations and forest structure and composition that we conducted 30 years ago in a 238,000-ha commercial forest landscape in northern Maine. The two study periods (1992-93 and 2021-22) marked either side of a landscape-scale transition in forest ownership and management. Code and supporting data files are provided for reproducing quantitative analyses and their associated figures: bootstrapping-derived 83.4% C.I.'s for per-forest-type densities across species, Delta-method-derived 83.4% C.I.'s for landscape abundances across species, Shannon's Diversity indices and associated statistical tests, generalized linear models of functional guild vs. abundance trend, and analyses of vegetation metrics collected at each bird survey site. See associated Figs under this Project heading.