WHAT IS THE VALUE OF A YELLOW PATCH? UNRAVELLING THE IMPORTANCE OF THE YELLOW COLORATION IN THE EUROPEAN SERIN

CIBIO-InBIO researchers Sandra Trigo and Paulo Gama Mota unveil the indirect role played by yellow carotenoid colouration in the condition, health and reproductive success of European serin (Serinus serinus).

By conditioning the availability of carotenoids (β-carotene) in the diet of a set of yellow males during moult, the researchers were able to observe that a richer diet in this pigment led to increased plasma carotenoid concentration and also to a higher immune response. In addition, they also noticed that supplemented males had a more saturated plumage coloration than their counterparts, leading them to be preferably chosen by females when subjected to a mate choice test.

This study, recently published by the journal Behavioral Ecology and Sociobiology is very interesting as it brings together key elements associated with the evolution of signals through sexual selection. In fact, while several studies have established the association between signals and i) health condition; ii) immune response; and iii) partner choice, this is the first one in which all these associations are established for the same individuals in the one species.

The findings obtained show that variations in the diet of serins determine the expression of a trait based on carotenoid concentration, which is subject to sexual selection. The differences detected serve as a health indicator, as they impact on the immune condition of the animals. In addition to increasing the concentration of carotenoids in the blood stream, enriched diets in these pigments lead to an enhance plumage ornament expression, which improves the males’ attractiveness to females. Thus, the mechanisms identified, ultimately affect the reproductive success of males, by conditioning their access to reproduction.

To find out more about this study, you can read the original article:
Trigo S, Mota PG (2015) What is the value of a yellow patch? Assessing the signalling role of yellow colouration in the European serin. Behavioral Ecology and Sociobiology. DOI: 10.1007/s00265-014-1860-2.