FEMALE PIED FLYCATCHERS PREFER BRIGHTLY COLORED MALES

In birds, it has proved difficult to demonstrate conclusively that fem ales prefer particular male traits. One problem is that females may sa mple few males before settling. To circumvent this problem, the mate s ampling behaviour of female pied flycatchers, Ficedula hypoleuca, was followed in the field by using video-cameras, and the plumage colours of the accepted and the rejected males were compared. Females mated pr eferentially with the more brightly coloured males. In territorial spe cies, another problem in the study of mate choice has been to separate the effect of female choice on the male trait from the effects of ter ritorial quality and other male characteristics, since they will often be intercorrelated. In aviary experiments, the effect of territory qu ality was controlled for by giving females a mating option between a b right and a dull male, each occupying a nestbox in compartments of the same size. In one experiment, females could choose between males with natural plumage colours (bright versus dull). In another experiment, the effects of age and behavioural correlates of male plumage colour w ere controlled for by painting one of two dull males bright black. In both these aviary experiments, females preferred the more brightly col oured male. This shows that male plumage colour per se represents a cu e for mate choice by female pied flycatchers.