Long-tailed Jaeger

Long-tailed Jaeger (Stercorarius longicaudus) is the smallest jaeger, slim-winged with exceptionally long central tail streamers in breeding adults. 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 breeds on high Arctic tundra, feeding on rodents and insects, then migrates far offshore across the world's oceans. 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).