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Young male blackcaps with blood parasite coinfections cope with oxidative stress favouring anthocyanin-rich food during migratory fattening
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  • Lucía Jiménez-Gallardo,
  • Jimena López-Arrabé,
  • Javier Pérez-Tris,
  • Carolina Remacha
Lucía Jiménez-Gallardo
Complutense University of Madrid Faculty of Biological Sciences
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Jimena López-Arrabé
Complutense University of Madrid Faculty of Biological Sciences
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Javier Pérez-Tris
Complutense University of Madrid Faculty of Biological Sciences

Corresponding Author:[email protected]

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Carolina Remacha
Complutense University of Madrid Faculty of Biological Sciences
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Parasites may alter host physiology, which may promote behavioural adaptations to counteract their effect. Adaptive feeding may help individuals to cope with infection, especially during physiologically highly demanding life stages. For instance, migrating birds need to fuel long-distance flights and repair oxidative damage caused by intense aerobic exercise, and parasites may influence on how individuals balance these needs. Infected birds may face increased oxidative challenges, which could induce them to favour antioxidant defences over other needs, such as fattening. We tested whether migrating birds can adaptively choose food according to their needs, favouring dietary antioxidants to cope with oxidative stress caused by blood parasites during migration. During autumn migration, we mist-netted young male European blackcaps (Sylvia atricapilla) stopping over in central Spain. We placed the birds in cages where they were offered fat and anthocyanin-enriched food alternatives. We measured preference for each food offer. We tested their infections by haemosporidian parasites with PCR techniques and their parasitaemia with blood smear inspection. We also measured physiological variables that account for nutritional and oxidative status in red blood cells and plasma. We found that birds with multiple infections favoured anthocyanin-enriched food controlling for an effect of body mass on food preference (lean blackcaps preferred anthocyanins, likely because they are urged to repair oxidative damage upon arrival on stopover with depleted energy reserves). Infected birds had a lower antioxidant capacity of plasma, and individuals with more oxidative damage preferred anthocyanin-enriched food. Our results suggest that parasite infections may increase individuals’ antioxidant needs, which could affect migration performance if the urge to find dietary antioxidants reduces fuel consumption rate.
06 Sep 2023Submitted to Journal of Avian Biology
08 Sep 2023Assigned to Editor
08 Sep 2023Submission Checks Completed
08 Sep 2023Review(s) Completed, Editorial Evaluation Pending
12 Sep 2023Reviewer(s) Assigned