Diverse natal dispersal in four sibling red kites originating from Austria, including wintering in Tunisia

Four red kites ( Milvus milvus ), (siblings, RK1, RK2, RK3 and RK4) from the same nest in north-eastern Austria were tagged with telemetry (GPS/GSM/UHF) loggers on 23 June 2018 during the pulli growth stage and tracked until 5 April 2019. RK1 (female), RK2 (male), RK3 (female) and RK4 (female) occupied post-fledging areas until 1 August 2018 when they then began to migrate following a south-eastern direction. RK1 wintered in central Italy and used three temporary settlement areas (TSA). RK2 and RK3 migrated to the Croatian coast of the Adriatic Sea and returned back to winter in their natal area. They used three and two TSA, respectively. RK4 reached the Italian coast of the Tyrrhenian Sea, crossing the sea in 12 h with an average flight speed of 58.6 km·h −1 ). The bird flew at an average altitude of 429 m above sea level before arriving in Algeria. RK4 then crossed the neighbouring border and wintered in Tunisia. It used two TSA (one in the Czech Republic and one in Tunisia). The migration behaviour and wintering locations among these floaters with the same genetic background during natal dispersal was substantially different and supposedly influenced by various environmental factors rather than by genetics.