title: Isotope signatures in winter moulted feathers predict malaria prevalence in a breeding avian host.
abstract: It is widely accepted that animal distribution and migration strategy might have co-evolved in relation to selection pressures exerted by parasites. Here, we first determined the prevalence and types of malaria blood parasites in a breeding population of great reed warblers Acrocephalus arundinaceus using PCR. Secondly, we tested for differences in individual feather stable isotope signatures (delta (13)C, delta (15)N, deltaD and delta (34)S) to investigate whether malaria infected and non-infected birds had occupied different areas in winter. We show that birds moulting in Afro-tropical habitats with significantly higher delta (13)C and delta (15)N but lower deltaD and delta(34)S values were more frequently infected with malaria parasites. Based on established patterns of isotopic distributions, our results indicate that moulting sites with higher incidence of malaria are generally drier and situated further to the north in West Africa than sites with lower incidence of malaria. Our findings are pertinent to the general hypothesis that animal distribution and particularly avian migration strategy might evolve in response to selection pressures exerted by parasites at different geographic scales. Tradeoffs between investment in energy demanding life history traits (e.g. migration and winter moult) and immune function are suggested to contribute to the particular choice of habitat during migration and at wintering sites.
authors.affiliation: Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, P.O. Box 1564, 82305, Starnberg (Seewiesen), Germany. yohannes@erl.orn.mpg.de
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Yohannes
authors.forename: Bengt
authors.initials: B
authors.lastname: Hansson
authors.forename: Raymond W
authors.initials: RW
authors.lastname: Lee
authors.forename: Jonas
authors.initials: J
authors.lastname: Waldenström
authors.forename: Helena
authors.initials: H
authors.lastname: Westerdahl
authors.forename: Mikael
authors.initials: M
authors.lastname: Akesson
authors.forename: Dennis
authors.initials: D
authors.lastname: Hasselquist
authors.forename: Staffan
authors.initials: S
authors.lastname: Bensch
mesh_terms: D000354:Africa, Western / Q000453:epidemiology; D025041:Animal Migration; D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis; D003903:Deuterium / Q000032:analysis; D017753:Ecosystem; D005241:Feathers / Q000737:chemistry*; D005843:Geography; D016015:Logistic Models; D008289:Malaria, Avian / Q000453:epidemiology*; D018978:Molting; D015999:Multivariate Analysis; D009587:Nitrogen Isotopes / Q000032:analysis; D015995:Prevalence; D012621:Seasons; D020308:Songbirds / Q000469:parasitology*; D013460:Sulfur Isotopes / Q000032:analysis; D014329:Tropical Climate
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D013460:Sulfur Isotopes; D003903:Deuterium