Historical Occupancy of the Yellow-green Grosbeak Caryothraustes canadensis (Aves, Cardinalidae) in the Far North of the Atlantic Forest.

Determining how environmental factors influence species occupancy patterns is essential to establish more efficient management strategies and policies for conserving natural populations and habitats. The Yellow-green Grosbeak (Caryothraustes canadensis) is a canopy specialist bird that occurs in the Atlantic Forest and represents a good model for evaluating how changes in regional scale characteristics can affect occupancy patterns of forest specialist species. Increasingly, occupancy models are being used to maximize these predictions because they are statistical methods that account for imperfect detection, which strengthens inferences compared to other approaches. We evaluated how multiple environmental factors affected the large-scale occupancy of C. canadensis over the last 30 years in the far north of the Brazilian Atlantic Forest, a recognized center of endemism and biodiversity. In this study, we collected secondary data from C. canadensis between 1991 and 2020. The occupancy of C. canadensis and several environmental factors that explain the historical occupancy dynamics of the species in the northern Atlantic Forest region were determined, and analyses were conducted with single-season occupancy models. The diurnal temperature range had the most significant impact on occupancy. Climate stability and the forest area were determining factors in the large-scale occupancy of C. canadensis. Other impacts on occupancy were noted as altitude and secondary effects due to precipitation. Records of C. canadensis in the region are probably associated with multiple interaction factors. The preservation of forested and climatically stable habitats of the region should favor the establishment of forest specialist species such as C. canadensis within the study region. The more significant climatic instability present along the final portion of the Sao Francisco River, probably a consequence of the loss of forest cover, can be considered an area that requires more urgent action for the conservation of this forest specialist species. Thus, our data validate the importance of forest remnants and reinforce the adverse effects of habitat fragmentation and degradation on the requirements of endemic bird populations of the Atlantic Forest.