Abstract
I conducted the second austral autumn raptor count at Concepción Watch Site in the eastern Bolivian lowlands to document species composition, timing, and abundance of migrating raptors between 10 March and 6 April 2009. I counted migrants for 26 days (134.5 hrs) recording 6,979 migrating raptors of 16 species. Mississippi Kites (Ictinia mississippiensis) comprised 80% (n = 5,571), Black Vultures 11% (Coragyps atratus, n = 747), and Snail Kites 5% (Rostrhamus sociabilis, n = 396). The remaining 4% (n = 265) included 13 species and other unidentified raptors. I also recorded non-raptor species on migration from the lookout, including 36 Maguari Storks (Ciconia maguari), a flock of 11 Anhinga (Anhinga anhinga), and thousands of Barn Swallows (Hirunda rustica). My observations confirm previous records suggesting a significant raptor migration occurs at the Concepción Watch Site in the austral autumn. Raptor monitoring should continue at Concepción annually and the site used to promote raptor conservation and awareness in Bolivia.