Uropygial gland size and composition varies according to experimentally modified microbiome in Great tits

摘要: Background: Parasites exert important selective pressures on host life history traits. In birds, feathers are inhabited by numerous microorganisms, some of them being able to degrade or lead infections. Preening with secretions the uropygial gland has been found act as an antimicrobial defence mechanism, expected regulate feather microbial communities and thus limit abrasion Here, we used experimental approach test whether Great tits (Parus major) modify their investment in response differences environmental microorganisms. Results: We that males, but not females, modified size when exposed higher bacterial densities feathers. also identified 16 wax esters secretions. The relative abundance these changed males while others only females greater loads Conclusion: Birds live a world composed commensal pathogenic This study provides first evidence for modifications defensive trait is microorganisms wild bird.