KEEPING THEIR COLOUR BRIGHT: PLUMAGE MAINTENANCE BEHAVIOUR IN EUROPEAN SERINS

In an article recently published by the journal Ibis, researchers Ana Leitão and Paulo Gama Mota (CIBIO-InBIO and University of Coimbra) show that the investment made by male European serins (Serinus serinus) in plumage maintenance is dependent on their coloration levels.

In a previous study, published last March by the journal Behavioral Ecology and Sociobiology, Sandra Trigo and Paulo Gama Mota had demonstrated that European Serin females prefer more colourful males, whose plumage contains higher concentrations of carotenoids. Plumage coloration in birds is used in signalling, but it is generally assumed to be a relatively fixed trait, which only changes when birds moult their plumage. However, it is known that birds spend much time in maintenance behaviour, cleaning their feathers and removing dust, behaviours that can affect the appearance of their plumage.

Having this in mind, the researchers began to hypothesize whether or not maintenance behaviour varied according to male coloration levels. Specifically, they formulated the following questions:

1. Do more colourful and attractive males spend more time maintaining their plumage?
2. Is their behaviour identical irrespective to colour attractiveness?
3. Is the behaviour of males affected by the presence of females?

By performing female mate-choice trials and measuring male plumage maintenance behaviour in a set of these animals, the researchers found that more colourful males spend more time in plumage maintenance than less colourful ones. And this maintenance does not seem to be related with the levels of ectoparasites in their plumage. Alternatively, this behaviour may stem from the fact that these animals may have more to gain in attractiveness by engaging in it; or that they can afford more time in maintenance behaviour. Interestingly, the team also noticed that the behaviour of males is not influenced by the presence of females.

To know more about this study, please read the original article:
Leitão AV, Mota PG (2015) Colourful male European Serins Serinus serinus are more careful with their plumage. Ibis, 157(3): 637-641. DOI: 10.1111/ibi.12257.