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Fülöp A, Czirják GÁ, Pap PL and Vágási CI 2016. Feather-degrading bacteria, uropygial gland and feather quality in House Sparrows Passer domesticus. Ibis (in press).
Abstract: Feathers are dead integumentary structures that are prone to damage and thus show gradual degradation over the course of a year. This loss of quality might have negative fitness consequences. Feather-degrading bacteria (FDB) are one of the most prevalent organisms that degrade feathers, yet the relationship between FDB load and flight feather quality has rarely been assessed. We studied this relationship in free-living House Sparrows Passer domesticus during two different annual lifecycle stages (breeding and non-breeding). We also considered the size of the uropygial gland (UG), given the antimicrobial function of its secretions, and the effect of body condition. We found that the number of feather holes was positively associated with FDB load and was negatively related to UG size and body condition during the breeding season in both sexes. In the non-breeding season we recovered the same relationships, but only in females. The degree of feather wear was unrelated to any of the variables measured during the breeding season, while it was negatively associated with UG size and positively with FDB load in the non-breeding season, but only in females. Our results suggest that FDB may induce the formation of feather holes, but only play a minor role in the abrasion of flight feathers.
Keywords: keratinolytic microorganisms, preen oil, feather hole, feather wear, feather structure
Image source: Journal of Experimental Biology