Broad-Winged Hawks Overwintering in the Neotropics: Landscape Composition and Threats in Wintering Areas of a Long-Distance Migrant

Abstract

The Broad-winged Hawk (Buteo platypterus) is an obligate long-distance migrant that breeds in deciduous and mixed forests of North America and migrates to Neotropical regions to overwinter. Despite advances in understanding the breeding ecology and migration of this species, the overwintering period and associated threats remain understudied. We used telemetry data to quantify land cover composition and threats during the overwintering period of seven females affixed with Argos solar-powered transmitters between 2014 and 2018. Broad-winged Hawks in our study nested in Pennsylvania, USA, and overwintered in Colombia, Brazil, and Peru. Overwintering areas varied in size (x¯ = 243.6 ± 101.2 km2) and were composed of evergreen sub-montane forests, lowland non-flooded forests, and lowland flooded evergreen forest. In general, the loss of forest cover in all areas used by Broad-winged Hawks in our study did not exceed 10% of the total overwintering area used, suggesting Broad-winged Hawks may select wintering areas with little forest disturbance. Illegal mining was a common disturbance in areas used by Broad-winged Hawks overwintering in southern Peru, and forest fires were the prevalent disturbance in the overwintering area of Mato Grosso in western Brazil. These results provide the first analysis of land cover composition and threats of Broad-winged Hawks during the overwintering period. Although more data are needed to determine specific habitat selection for this species, our study suggests large forested areas in the Neotropics are key to ensure the conservation of the Broad-winged Hawk during the overwintering period, an understudied stage of its annual cycle.