Farallon de Medinilla is a small island in the western Pacific that is leased by the U.S. military from the Commonwealth of the Northern Mariana Islands as an impact area for training exercises. We spent 5.5 h on the island surveying its avifauna on 4 Nov. 1996 and observed a total of 17 species including seabirds, migratory shorebirds, and resident landbirds. Of special interest was the first island record of the endangered Micronesian Megapode (Megapodius laperouse) and breeding colonies of Great Frigatebirds (Fregata minor) and Masked Boobies (Sula dactylatra). Locations of individual megapodes and seabird colonies were mapped and breeding information recorded. Historical records and photographs indicate that since the island has been used as an impact area its vegetative structure has changed from a medium-height, relatively closed canopy forest, to primarily open areas with intermittent patches of low forest. Alterations of native vegetation likely resulted in changes in the density, distribution, and species composition of the island's avifauna, although these changes are difficult to quantify.