Migrant Land Birds and Water Birds in the Mariana Islands

Abstract

Approximately 56 species of land and freshwater birds have been recorded as migrants or vagrants in the Mariana Islands, but few occur in substantial numbers. Common migrants include the Tufted Duck (Aythya fuligula), Northern Pintail (Anas acuta), and Cattle Egret (Bubulcus ibis). Several other heron and duck species appear most years in small numbers. The Barn Swallow (Hirundo rustica) is the only regular migrant land bird. A similar assemblage of herons and waterfowl has been reported from the Ogasawara and Iwo Islands to the north. Many more species of migrant land birds occur in the Ogasawara and Iwo groups and in Palau to the southwest, which are closer to large land masses.