RT Journal Article
T1 A trans‐African migrant shows repeatable route choice in males and repeatable timing in females
A1 Vansteelant, Wouter M. G.
A1 Gangoso De La Colina, Laura Esther
A1 Viana, Duarte S.
A1 Shamoun‐Baranes, Judy Z.
A1 Figuerola, Jordi
AB Migrant bird populations often show substantial variation in route choice and timing. Determining whether this population-level variation is driven by between-individual differences and/or flexibility within individuals is key to identifying drivers of migration patterns. ‘Repeatability' (R, the proportion of population-level variation attributable to between-individual variation) has become a central metric for the relative consistency of individual behaviour. Individual repeatability in migratory route choice and timing is often reported to vary between seasonal and regional contexts and may also differ between demographic groups (e.g. sexes), but interpreting repeatability requires careful consideration of the underlying changes in between- and within-individual variation. We GPS-tracked repeat migrations for eight male and five female Eleonora's falcons Falco eleonorae and quantified the magnitude of within- and between-individual variation and the individual repeatability of their seasonal routes and timing at 100 km intervals all across Africa. We did this across both sexes, and then separately for males and females. We found greater between-individual variation in spring routes, albeit with substantial regional fluctuations in both seasons. The greatest between-individual variation in routes occurred during the spring desert-crossing, but this coincided with high within-individual variation, and thus only low repeatability of route choice. Route repeatability instead peaked (R = 0.6–0.8) through the Horn of Africa in spring, and during the rainforest-crossing in autumn. Variation and repeatability of timing was stable across regions, with generally higher between-individual variation and repeatability in spring. Sex-specific analyses suggest males exhibit higher route repeatability, while females exhibit stronger seasonal contrasts in timing repeatability. Such sex differences were unexpected, but overall, between-individual variation and repeatability in routes and timings appear greater where environmental and annual cycle constraints are weaker. Route repeatability is especially high where falcons show fidelity to stop-over sites, or individual barrier-crossing preferences. Individual routines may be acquired through early-life exploration-refinement.
PB John Wiley & Sons / Nordic Society Oikos
SN 0908-8857
YR 2023
FD 2023
LK https://hdl.handle.net/20.500.14352/110729
UL https://hdl.handle.net/20.500.14352/110729
LA eng
NO Vansteelant, W. M. G., Gangoso, L., Viana, D. S., Shamoun‐Baranes, J. Z., & Figuerola, J. (2023). A trans‐African migrant shows repeatable route choice in males and repeatable timing in females. Journal of Avian Biology, 2023(9-10), e03050. https://doi.org/10.1111/jav.03050
NO The study was supported by the Cabildo de Lanzarote, European Social Fund, and adaptation and improvement of the internationalization of e-infrastructure of the ICTS-RBD for the ESFRI-LifeWatch. Project coordinator LG was supported by the Marie Skłodowska-Curie Actions of the EU Commission (project ‘EcoEvoClim', grant no. 747729). WMGV led the research supported by a Juan de la Cierva Formación fellowship (grant no. FJCI-2017-34396).
NO Cabildo de Lanzarote
NO European Social Fund
NO Centro Superior de Investigaciones Científicas (España)
NO European Commission
NO Ministerio de Ciencia, Innovación y Universidades (España)
DS Docta Complutense
RD 21 abr 2025