The Wallace's hawk-eagle (Nisaetus nanus, earlier under the genus Spizaetus), is a species of bird of prey in the Accipitridae family. It is found in Brunei, Indonesia, Malaysia, Myanmar, and Thailand. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss. It is among the smallest eagles in the world at about 46 cm (18 in) long and weighing 500–610 g (1.10–1.34 lb) (about the size of a peregrine falcon). It is named after Alfred Russel Wallace, a British naturalist, explorer, geographer, anthropologist and biologist.