Assessment of habitat suitability for the globally threatened Cock-tailed Tyrant Alectrurus tricolor (Passeriformes: Tyrannidae)

Abstract

Cock-tailed Tyrant Alectrurus tricolor (Vieillot, 1816), a Vulnerable South American grassland specialist, is facing substantial habitat loss due to land-use change by agricultural and forestry expansion. This study aims to assess the current distribution and suitable habitat availability for Cock-tailed Tyrant using species distribution modelling (SDM) and recent distributional data from the Global Biodiversity Information Facility (GBIF). Occurrence data from 1,583 records, mapped by season and habitat type, were used to generate a MaxEnt model with a high predictive accuracy (AUC = 0.974). Results revealed three main distributional clusters: one in Brazil, another spanning Mato Grosso do Sul, Paraguay and north-eastern Argentina, and a separate group in the Bolivian lowlands. Seasonal analysis found no significant distributional shifts, supporting previous findings of the species’ non-migratory behaviour. Key environmental contributors to habitat suitability included ecoregion type, precipitation, and vapour pressure. The predicted suitable habitat covers approximately 177,753 km². These findings underscore the urgent need for conservation efforts focusing on critical grassland habitats, particularly within the Cerrado, Southern Cone Mesopotamian grasslands, and Beni savanna biomes. Sustainable land-use practices, grassland restoration, and periodic habitat reassessments are essential to preserve Cock-tailed Tyrant populations and support the biodiversity of South American grasslands.