Potential distribution of the Crowned Eagle (Buteogallus coronatus) in South America

Predictive models of species distribution are a good source of quantitative information for making conservation decisions. Knowledge about the Crowned Eagle (Buteogallus coronatus), a South American species endangered by IUCN, is scarce and in many areas is limited to records in various environments. In this study we determined the potential distribution of the Crowned Eagle in South America through a bioclimatic niche model. We obtained 698 records of the species that were combined with 20 bioclimatic variables and a LandCover coverage variable in a maximum entropy model with the Maxent program. The area under the curve was 0.88 indicating that the model has good discriminative capacity. The seasonality of T ° and the average T ° of the rainiest quarter were the most important variables to explain the presence of the species while the cover variable was not relevant. The area weighted by the habitat suitability given by the model and using the size of territory estimated by the minimum distance between occupied nests suggests that the South American population would not exceed 9132 reproductive pairs. The model indicates two large areas with greater probability of presence: Humid Chaco and Serrano, Monte and Espinal in Argentina and savannahs in central-eastern Brazil. Although these results should be taken with caution, the present model is a first step to objectively estimate the possible population size of the species as well as to identify potential areas of presence.