Distribution, ecology and conservation status of the Blue-headed Macaw Primolius couloni

Until recently thought to be secure (i.e. Least Concern), the Blue-headed Macaw is now classified as Endangered in the IUCN Red List, based on an apparent decline and a population estimate of <2500 mature individuals. We review published and unpublished sources, collating records from 61 localities in Peru, Brazil and Bolivia, and compiling information on habitat use, seasonality, group size, demography, and population density. We find the species to be associated with disturbed habitats at one site, but a broader analysis revealed no significant associations with forest type, riverine habitats, degree of disturbance or altitude. By mapping locality records, and accounting for discontinuities, we calculate an Extent of Occurrence of 460,000 km2. Range-wide data on encounter rates and flock sizes suggest that the species is sedentary and gregarious, with an overall population density of one mature individual per 10-50 km2. Our figures for range size and density (both highly conservative) indicate that the global population estimate should be revised upwards to 9200-46,000 mature individuals. Balanced against an increasing threat from trade, these data argue for a reversal in status to Vulnerable, with a shift to Near Threatened possible in future. Given these recent fluctuations in conservation status, the Blue-headed Macaw provides valuable insight into the difficulties of using IUCN Red List criteria to assess poorly known taxa. Red List assessments should be based on extensive reviews where possible, and analyses using Red List data should consider effects of data quality.