Effect of Tyrosine on the Melanins of the Species Serinus canaria

Tyrosine is a nonessential polar amino acid that plays a central role in the biosynthesis of melanins, the pigments responsible for the dark coloration of plumage, skin, and keratinized structures in birds. In canaries (Serinus canaria), dietary tyrosine intake can influence the intensity and uniformity of melanization, particularly in birds belonging to the “Black” type, characterized by a high presence of eumelanin. Some amino acids, such as phenylalanine and tyrosine, are involved in the biosynthesis of melanins, indicating a direct link between nutrition and the quality of the melanic phenotype. The aim of this paper is to analyze the biochemical mechanisms and the resulting phenotypic outcomes through which tyrosine modulates pigmentation in canaries, including a brief mention of potential side effects resulting from improper use.