Declining throughout its range, the Swainson\'s Hawk\'s dependence on open prairies and arid grasslands for its nesting and prey, such as small mammals, lizards and birds, may be related partially to changing agricultural practices and increasing disturbance of isolated nesting trees. This large, soaring hawk migrates 1000s of kilometers south to winter in the grasslands of northern Argentina. Here recent increases in uses of insecticides against marauding grasshoppers, the main food of Swainson\'s Hawks during the winter, may also be a contributing factor to its decline. Flocks of 10,000 or more individuals have been seen migrating high over head together in the Amazon. Some individuals are all black but most are brown and white.
The four-digit banding code is SWHA.