Being an obligate parasite, juvenile common cuckoos Cuculus canorus are thought to reach

their African wintering grounds from Palearctic breeding grounds without guidance from

experienced conspecifics but this has not been documented. We used satellite tracking to

study naïve migrating common cuckoos. Juvenile cuckoos left breeding sites in Finland

moving slowly and less consistently directed than adult cuckoos. Migration of the juveniles

(N = 5) was initiated later than adults (N = 20), was directed toward the southwest±significantly

different from the initial southeast direction of adults±and included strikingly long Baltic

Sea crossings (N = 3). After initial migration of juvenile cuckoos toward Poland, the

migration direction changed and proceeded due south, directly toward the winter grounds,

as revealed by a single tag transmitting until arrival in Northwest Angola where northern

adult cuckoos regularly winter. Compared to adults, the juvenile travelled straighter and

faster, potentially correcting for wind drift along the route. That both migration route and timing

differed from adults indicates that juvenile cuckoos are able to reach proper wintering

grounds independently, guided only by their innate migration programme.