Adaptive Features of the Avian Integument: A Comparative Study of the Laughing Dove, Quail, Muscovy Duck, With Emphasis on the Preen Gland Secretions and Associated Microbial Communities.

The current work compared the integumentary architecture and feather microbiomes among three avian species inhabiting different ecological niches: the aerial laughing dove (Spilopelia senegalensis), the terrestrial quail (Coturnix coturnix), and the semi-aquatic Muscovy duck (Cairina moschata). Histological, histochemical, and microbial analyses revealed clear interspecific variations that appear to be associatedwith the distinct lifestyles of the examined species. The laughing dove exhibited the thinnest skin, numerous Herbst corpuscles, and a pigmented epidermis, features related to the aerial mode of life and serving to mitigate the frequent exposure to sunlight. in contrast, the quail showed moderately thick epidermis, non-pigmented skin, and less pronounced dispersal of mechanoreceptors, reflecting its tendency toward the ground-dwelling lifestyle. While the Muscovy duck possessed the thickest skin, characterized by the highest microbial load, which aligns with its semi-aquatic habitat and frequent water contact. Furthermore, the preen secretions of the laughing dove exhibited strong antimicrobial potency, while those of the Muscovy duck were functionally engaged in waterproofing rather than microbial combating. Collectively, these findings highlight how skin architecture and microbial populations modulate in response to the environmental challenges, such as ecological demands and the surrounding microenvironment.