NEW LOCALITIES FOR THE BLACK-FACED HAWK (LEUCOPTERNIS MELANOPS) SOUTH OF THE AMAZON RIVER AND DESCRIPTION OF THE IMMATURE PLUMAGE OF THE WHITE-BROWED HAWK (LEUCOPTERNIS KUHLI)

摘要

The Black-faced Hawk (Leucopternis melanops) and White-browed Hawk (L. kuhli) are forest-based, Amazonian raptors whose distributions have been considered to be mutually exclusive north and south of the Amazon River, respectively. The occurrence of L. melanops south of the river was first indicated by a specimen collected by A. M. Olalla on the lower Tapajos River > 70 years ago. The provenience of this specimen has been contested by diverse authors but both species were recently captured at localities along the lower Tapajos, corroborating the coexistence of L. melanops and L. kuhli in this region. We present four new specimen localities for L. melanops in southern Amazonia, greatly amplifying its known distribution. We also describe the immature plumage of L. kuhli based on three specimens that had been identified as L. melanops.