Short-tailed Shearwater

Short-tailed Shearwater (Puffinus tenuirostris) is a medium-sized dark shearwater with a compact head, short bill and narrow wings suited to sustained oceanic flight. 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 in burrows around Tasmania and nearby islands, migrates far into the North Pacific and feeds on krill, fish and squid by diving and surface-seizing. 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).