Unusual clockwise loop migration lengthens travel distances and increases potential risks for a central Asian, long distance, trans-equatorial migrant, the Red-footed Falcon Falco vespertinus

Abstract

Capsule: Red-footed Falcons Falco vespertinus migrating from northern Kazakhstan proceed west before heading south to Africa; their northbound travel follows a different route with passage close to shooting hotspots in the Mediterranean. Aim: To use tracking and ringing data to document for the first time the migration of globally threatened Red-footed Falcons from northern Kazakhstan. Methods: Light-level geolocators were deployed on breeding adults in Kazakhstan and recovered one year later. Ringing and observational data from more than 100 years of Russian-language and other literature were summarized and mapped alongside the geolocator data. Results: Geolocator, ringing and observational data together demonstrate that Red-footed Falcons from northern Kazakhstan have a clockwise loop migration that begins with a long and unusual westward trek around eastern Europe’s large inland seas before continuing to extreme southern Africa. Return migration is farther west and requires crossing two major migratory barriers: the Sahara and the Mediterranean. Conclusion: The loop migration we describe requires an extensive longitudinal movement, exposes central Asian Red-footed Falcons to multiple desert, mountain and marine crossings, and, at outbound and return Mediterranean bottlenecks, crosses sites where raptor shooting is common.