Light-Level Geolocators Reveal that White-Throated Needletails (Hirundapus caudacutus) Follow a Figure-Eight Migration Route between Japan and Australia1

Migratory birds travel over long distances twice a year throughout the course of their lives. Knowledge on the routes and travel patterns among linked areas is essential for migratory bird conservation and international population monitoring. In this study, we tracked the full migration of three White-throated Needletails (Hirundapus caudacutus) breeding in northern Japan using light-level geolocators. The migration routes for all the individuals were similar and followed a “figure 8” pattern overall. The destination of all the birds was eastern Australia. This migration route between northern Japan and eastern Australia follows the land arrangements in East Asia to Australia to some extent, but long-distance offshore movements were also observed. None of the three individuals had a notably constant location during the period in Australia. The migration routes of two of the birds were similar. This is the first report on the migration of a swift species in the East Asian–Australasian Flyway.