title: First-Time Migration in Juvenile Common Cuckoos Documented by Satellite Tracking.
abstract: 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.
authors.affiliation: Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Marta Lomas
authors.identifier: http://orcid.org/0000-0002-9397-8803
authors.initials: ML
authors.lastname: Vega
authors.affiliation: Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Mikkel
authors.initials: M
authors.lastname: Willemoes
authors.affiliation: Department of Biology, University of Turku, Turku, Finland.|FitzPatrick Institute of African Ornithology, University of Cape Town, Cape Town, South Africa.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Thomson
authors.affiliation: Department of Ecology, University of Oulu, Oulu, Finland.
authors.forename: Jere
authors.initials: J
authors.lastname: Tolvanen
authors.affiliation: Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland.
authors.forename: Jarkko
authors.initials: J
authors.lastname: Rutila
authors.affiliation: Department of Zoology and Laboratory of Ornithology, Palacky University, Olomouc, Czech Republic.
authors.forename: Peter
authors.initials: P
authors.lastname: Samaš
authors.affiliation: Department of Biology, Lund University, Lund, Sweden.
authors.forename: Roine
authors.initials: R
authors.lastname: Strandberg
authors.affiliation: Department of Zoology and Laboratory of Ornithology, Palacky University, Olomouc, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Grim
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.|Norwegian Institute for Nature Research (NINA), Sluppen, Trondheim, Norway.
authors.forename: Frode
authors.initials: F
authors.lastname: Fossøy
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.|Norwegian Institute for Nature Research (NINA), Sluppen, Trondheim, Norway.
authors.forename: Bård Gunnar
authors.initials: BG
authors.lastname: Stokke
authors.affiliation: Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Kasper
authors.initials: K
authors.lastname: Thorup
mesh_terms: D000810:Angola; D025041:Animal Migration; D000818:Animals; D001717:Birds / Q000254:growth & development / Q000502:physiology*; D005387:Finland; D017215:Satellite Communications; D012741:Sexual Maturation; D013997:Time Factors; D014919:Wind