An age-dependent fitness cost of migration? Old trans-Saharan migrating spoonbills breed later than those staying in Europe, and late breeders have lower recruitment
Lok, T.; Veldhoen, L.; Overdijk, O.; Tinbergen, J.M.; Piersma, T. (2017). An age-dependent fitness cost of migration? Old trans-Saharan migrating spoonbills breed later than those staying in Europe, and late breeders have lower recruitment. J. Anim. Ecol. 86(5): 998-1009. https://dx.doi.org/10.1111/1365-2656.12706 In: Journal of Animal Ecology. Blackwell Science/British Ecological Society: Oxford. ISSN 0021-8790; e-ISSN 1365-2656, more |   |
| Author keywords | breeding success; carry-over effect; evolution; life history; migration; post-fledging survival; recruitment, timing of breeding; wintering site |
| Authors | | Top | - Lok, T.
- Veldhoen, L.
- Overdijk, O.
| - Tinbergen, J.M.
- Piersma, T., more
| |
| Abstract | 1. Migration is a widespread phenomenon in the animal kingdom. On the basis of theconsiderable variation that exists between and within species, and even withinpopulations, we may be able to infer the (age- and sex-specific) ecological trade-offsand constraints moulding migration systems from assessments of fitness associatedwith migration and wintering in different areas.2. During three consecutive breeding seasons, we compared the reproductive performance(timing of breeding, breeding success, chick body condition and post-fledgingsurvival) of Eurasian spoonbills Platalea leucorodia that breed at a single breedingsite in The Netherlands, but migrate different distances (c. 4,500 vs. 2,000 km,eitheror not crossing the Sahara) to and from wintering areas in southern Europeand West Africa. Using mark–recapture analysis, we further investigated whethersurvival until adulthood (recruitment probability) of chicks hatched between 2006and 2010 was related to their hatch date and body condition.3. Long-distance migrants bred later, particularly the males, and raised chicks ofpoorer body condition than short-distance migrants. Hatch dates strongly advancedwith increasing age in short-distance migrants, but hardly advanced in longdistancemigrants, causing the difference in timing of breeding between long- andshort-distance migrants to be more pronounced among older birds.4. Breeding success and chick body condition decreased over the season, and chicksthat fledged late in the season or in poor condition were less likely to survive untiladulthood. As a result, long-distance migrants—particularly the males and olderbirds—likely recruit fewer offspring into the breeding population than short-distancemigrants. This inference is important for predicting the population-level consequencesof changes in winter habitat suitability throughout the wintering range.5. Assuming that the long-distance migrants—being the birds that occupy the traditionalwintering areas—are not the poorer quality birds, and that the observed agedependentpatterns in timing of breeding are driven by within-individual effects andnot by selective disappearance, our results suggest that the strategy of long-distance migration, involving the crossing of the Sahara to winter in West Africa, incurred acost by reducing reproductive output, albeit a cost paid only later in life. |
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