Biochemical and morphological features of the uropygial gland of the Chilean Flamingo and their functional implications

CHIALE, MARÍA CECILIA; CADIERNO, MARÍA PILAR; FERNÁNDEZ, PATRICIA; MIJAILOVSKY, SERGIO; HERAS, HORACIO; BARBEITO, CLAUDIO; MONTALTI, DIEGO

ZOOLOGY

ELSEVIER GMBH

Año: 2021 vol. 147

0944-2006

Flamingos inhabit specialized habitats and breed in large colonies, building their nests on islands that limit theaccess of terrestrial predators. Many aspects of their uropygial gland are still unknown. The uropygial gland, asebaceous organ exclusive to birds, shares some histological features among species such as the presence of acapsule, adenomers with stratified epithelium and secondary and primary chambers. We found that the uropygialgland of the Chilean Flamingo (Phoenicopterus chilensis) displays most of these characteristics but lacks a primarystorage chamber. This absence may be an adaptation to their aquatic environment. The uropygial secretion ofthis species has a variety of glycoconjugates while its lipid moiety is largely dominated by waxes and minoramounts of triacylglycerols and fatty acids. Mass spectrometry analysis of the preen wax showed branched fattyacids of varied chain length and unbranched fatty alcohols, resulting in a complex mixture of wax esters and nodifferences between sexes were observed. The glycoconjugates present in the preen secretion could play a role asantimicrobial molecules, as suggested for other bird species, while the absence of diester waxes in flamingosmight be related with their nesting habits and limited exposure to predation. Our results were evaluated accordingto physiological and ecological aspects of the flamingo?s biology.