A long-winged bird that catches insects in flight and visits Japan in summer.
Adults are mostly dark brown with a white rump and long, sickle-shaped wings.
Pacific Swifts do not use exactly the same route in both migration seasons. Researchers fitted light-level geolocators to three birds on Sakhalin and tracked a journey of almost 10,000 km to Australia. Rather than stay over open sea, the birds detoured from Sakhalin to the nearby Asian mainland at Primorye, then continued through Indochina and Indonesia to northern Australia. Their southbound autumn migration took an average of 12 days longer than the northbound spring journey.
Stopovers also differed: on the way north, birds paused in Indonesia closer to their Australian wintering grounds. The three tracked swifts made more stopovers in spring, with shorter stays at each site; total stopover time was similar between seasons.
IUCN Red List · Least Concern (LC) · Global species-level assessment
BirdLife International’s 2024 global assessment lists the Pacific Swift as Least Concern (LC) with a stable population trend; the number of mature individuals has not been quantified. Japan’s 2026 Red Databook assesses the summer-visiting subspecies Apus pacificus kurodae as Vulnerable (VU). In surveys south of Honshu, routes recording the subspecies fell from 99 in 1997–2002 to 53 in 2016–2021, while recorded birds declined from 1,492 to 458. The Ministry notes that other birds feeding on flying insects have also declined and suggests that foraging conditions may have worsened. It cautions that the surveys were more than ten years apart and flocking can make counts variable. The global species assessment and Japan’s subspecies assessment cover different populations and geographic scopes.