Distribution and migration of Mississippi Kites in South America

Abstract

Mississippi Kites (Ictinia mississippiensis) are trans-equatorial, long-distance migrants that breed in North America and overwinter in South America. Information about their migration routes and winter distribution intheNeotropicsismostlyanecdotal.BycompilingrecordsofMississippiKitesinSouthAmericafromtheliterature and previously unpublished observations (1904-2010), we identified 96 locality records (a location where a flock or individual was recorded) and 146 independent records of flocks (observations of flocks irrespective of year, location, or time of year). Our locality records included 38 (39%) during southbound migration (1 September-30 November), 18 (19%) during northbound migration (15 February-30 April), 38 (39%) during austral summer (1 December-14 February), and two (3%) during austral winter (1 May-31 August). Most Mississippi Kites (84, 88%) were observed between the 11 ◦ Sa nd 32 ◦ S latitudinal band in central South America. Of our independent records of flocks, 133 (92%) were observed between 11 ◦ Sa nd 32 ◦ S, 12 (7%) between 11 ◦ Na nd 10 ◦ S, and a lone vagrant (1%) between 33 ◦ Sa nd 43 ◦ S. Our data suggest that Mississippi Kites are common and widespread in the austral summer between 11 ◦ Sa nd 32 ◦ S in central South America. On the basis of the number of locality records (N = 52, 54%) and number of flocks of Mississippi Kites observed between 22 ◦ Sa nd 32 ◦ S( N = 61, 42%), the Chaco forest appears to be the main wintering grounds for the species. However, additional monitoring is needed to further test this hypothesis. A large portion of Chaco habitat is now under cultivation, and how this habitat transformation might influence the annual cycle of Mississippi Kites is unknown.