Browsing by Author "Willemoes, Mikkel"
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- Data packageData from: Flying on their own wings: young and adult cuckoos respond similarly to long-distance displacement during migration(2020-07-01) Thorup, Kasper; Vega, Marta L.; Snell, Katherine R.S.; Lubkovskaia, Regina; Willemoes, Mikkel; Sjöberg, Sissel; Sokolov, Leonid V.; Bulyuk, VictorCommon cuckoos Cuculus canorus are obligate nest parasites yet young birds reach their distant, species-specific wintering grounds without being able to rely on guidance from experienced conspecifics--in fact they never meet their parents. Naïve marine animals use an inherited navigational map during migration but in inexperienced terrestrial animal migrants unequivocal evidence of navigation is lacking. We present satellite tracking data on common cuckoos experimentally displaced 1,800 km eastward from Rybachy to Kazan. After displacement, both young and adult travelled similarly towards the route of non-displaced control birds. The tracking data demonstrate the potential for young common cuckoos to return to the species-specific migration route after displacement, a response so far reported exclusively in experienced birds. Our results indicate that an inherited map allows first-time migrating cuckoos to locate suitable wintering grounds. This is in contrast to previous studies of solitary terrestrial bird migrants but similar to that reported from the marine environment.
- Data packageData from: Intra-African movements of the African Cuckoo Cuculus gularis as revealed by satellite telemetry(2017-12-20) Iwajomo, Soladoye B.; Willemoes, Mikkel; Ottosson, Ulf; Strandberg, Roine; Thorup, KasperDespite many bird species migrating regularly within the African continent, in response to rainfall and breeding opportunities, documented evidence of the spatiotemporal patterns of such movements is scarce. We use satellite telemetry to document the year round movement of an intra-African migrant breeding in the savannah zone of sub-Saharan Africa, the African Cuckoo. After breeding in central Nigeria, the birds migrated to more forested sites in the Adamawa region of Cameroon (n=2) and western Central African Republic (n=1). Departure from the breeding ground coincided with deteriorating environmental conditions whereas arrival at the non-breeding sites matched period of increasing vegetation greenness. Migratory movements generally occurred during dark hours. In total, an average distance of 748 km in 66 days was covered during the post-breeding migration and 744 km in 27 days during return journey with considerable individual variation and with more stopover sites used during post-breeding migration. The diversity of migration routes followed suggests a relatively variable or flexible initial migration strategy, high individual route consistency as well as high fidelity for non-breeding grounds.
- Data packageData from: Remarkably similar migration patterns between different red-backed shrike populations suggest that migration rather than breeding area phenology determines the annual cycle(2020-10-03) Pedersen, Lykke; Onrubia, Alejandro; Vardanis, Yannis; Barboutis, Christos; Waasdorp, Stef; van Helvert, Monique; Geertsma, Marten; Ekberg, Per; Willemoes, Mikkel; Strandberg, Roine; Matsyna, Ekaterina; Matsyna, Alexander; Klaassen, Raymond H.G.; Alerstam, Thomas; Thorup, Kasper; Tøttrup, Anders P.The regular fluctuation of resources across the Globe guides movements of migratory animals. To ensure sufficient reproductive output and maintain viable population sizes, migratory animals should match arrival at breeding areas with local peaks in resource availability. It is generally assumed that breeding phenology dictates the timing of the annual cycle, but this is poorly studied. Here, we use light‐level geolocator tracking data to compare the annual spatiotemporal migration patterns of a long‐distance migratory songbird, the red‐backed shrike, Lanius collurio, breeding at widely different latitudes within Europe. We find that populations use remarkably similar migration routes and are highly synchronized in time. Additional tracks from populations breeding at the edges of the European range support these similar migration patterns. When comparing timing of breeding and vegetation phenology, as a measure of resource availability across populations, we find that arrival and timing of breeding corresponds to the peak in vegetation greenness at northern latitudes. At lower latitudes birds arrive simultaneously with the more northerly breeding populations, but after the local greenness peak, suggesting that breeding area phenology does not determine the migratory schedule. Rather, timing of migration in red‐backed shrikes may be constrained by events in other parts of the annual cycle.