Great Frigatebird

Great Frigatebird (Fregata minor) is a very large yet lightweight seabird with long angular wings and a deeply forked tail; breeding males inflate a red throat pouch. Body shape, bill structure, plumage pattern and voice provide the strongest field characters. Age, sex and season may alter its appearance, so identification should combine several features and careful direct field comparisons with similar species in the same habitat (Wikipedia, general species account).

It takes fish and squid from near the tropical ocean surface and sometimes steals catches from other birds, while breeding in island colonies in trees and shrubs. Its movements and social behaviour vary through the year, with breeding birds generally more dispersed and non-breeding birds gathering where food is concentrated. Japanese records place it within the country's documented avifauna as a resident, migrant or visitor (Wikipedia, general species account; Wildlife of Japan occurrence records).