Area of Sustainable Forest Habitat within the Mississippi Alluvial Valley Bird Conservation Region

Values for area of sustainable forest habitat for each species were obtained as the predicted occupied proportion of each 900 square meter pixel (i.e., occupancy probability x 900) within all forest patches deemed large enough to harbor a sustainable population of the species. The area required for a sustainable population of each species was derived from credible intervals associated with population trends from historical (1966-2015) BBS data (Sauer and others, 2017). For each silvicolous bird species in the Mississippi Alluvial Valley, we assumed the minimum sustainable population was the number of birds needed to ensure ≤1% probability that the population would be extirpated (i.e., drop below a quasi-extinction threshold) during a 100-year period wherein annual population change was randomly selected from the credible interval associated with each species’ population trend. We used the mean of 500 simulation replicates conducted in R (Version 3.4.4; https://www.r-project.org/) as the presumed minimum sustainable population for each species. We arbitrarily set the quasi-extinction threshold at 25 breeding pairs. Because species with credible intervals associated with their trend estimates that were inclusively positive never declined in population, by default these species had a minimum sustainable population of 25 pairs.