Secrets of the night: roost sites and sleep disturbance factors during the autumn migration of first‐year white stork <i>Ciconia ciconia</i>

The migration phase of birds is divided into two main states: stopovers and actual migratory flights. For soaring birds, such as storks, nighttime especially important to conserve energy start the next day in favourable weather conditions. Although there a large number recent studies on white stork Ciconia ciconia , for example using advanced technologies GPS technology, nocturnal behaviour species still an enigma. Thus, we GSM–GPS‐tagged 90 immature storks checked their behaviour, roost disturbance, during first autumn from breeding grounds southern Poland wintering places Africa. Storks roosted three types site: buildings, ground or trees. Birds that had higher probability disturbance than those used trees buildings. at night was also related longitude latitude; most easterly route were disturbed more often night. Furthermore, interestingly, environmental conditions roosts significantly disturbance; roosting tree sites with NDVI (greener) levels artificial light both lower disturbance. A possible explanation this could be potential predatory pressure We found after long flights night, migrated further day. better understanding well other use modern technological tools greater precision recommended.