Red-spotted Bluethroats Luscinia s. svecica migrate along the Indo-European flyway: a geolocator study

Capsule Red-spotted Bluethroats Luscinia s. svecica from two European breeding populations spent the boreal winter on the Indian sub-continent.

Aim Tracking the migration of Red-spotted Bluethroats from Europe to the hitherto unknown non-breeding areas and back.

Methods Light-level geolocators were deployed on male Bluethroats at breeding sites in the Czech Republic (n= 10) and in Norway (n= 30). Recorded light intensity data were used to estimate the locations of nonbreeding sites and migration phenology during the annual cycle.

Results Bluethroats spent the boreal winter in India (n= 3) and Pakistan (n= 1), on average more than 6000 km from their breeding areas. Autumn migration started in August (n= 1) or early September (n= 2), and lasted for 26–74 days. Spring migration commenced on 8 and 9 April (n = 2) and lasted for about a month. During both autumn and spring migration, birds stopped over two or three times for more than 3 days.

Conclusion This study for the first time showed where Red-spotted Bluethroats from European breeding populations stay during the boreal winter. This seems to be the first time that a passerine bird has been tracked along the Indo-European flyway.