Documenting birds over two centuries of deforestation in an Atlantic Forest region of Brazil

The first ornithological record from Parana State, Southern Brazil, dates from 1820, when forests covered 83% of the area. There is a lack of studies evaluating how knowledge on species richness increased over time, together with a massive deforestation process. We aimed to describe the changes, by decade, in forest species richness since that time, and to determine how field effort hours were distributed. We reviewed published studies using online databases. We compared forest bird communities between decades with Jaccard Dissimilarity Indices and compared communities' composition among decades with Analysis of Similarity. In 200 years, 421 forest bird species were mentioned. Most of the species were detected until 1980, a likely subset of the avifauna before habitat loss; fewer species (108) were recorded afterward. An increasing number of species (8-20) stopped being recorded by decade from the 1980s. Field effort hours were mentioned in 1984, remaining temporally and spatially uneven. More than 1,000 localities have been inventoried, but most species reports are from Eastern municipalities. Areas within Serra do Mar, Curitiba, and Londrina stand out as protected forests and well-known academic centers. Cerrado endemics corroborated the relevance of exploring different regions, but further studies in this domain are strongly recommended.