It is currently accepted that song complexity in birds has evolved partially by female preference. Although there is good evidence for this preference from laboratory experiments, most field studies have failed to show strong correlations between song complexity and female choice. It has been suggested recently that this may be due to the fact that the measures of reproductive success have not taken into account the extra-pair paternity that some males may achieve.
The study for which this scholarship is requested will examine how repertoire size relates to mate choice and reproductive success in the Willow Warbler (Phylloscopus trochilus), a species which shows very high variability in repertoire size. The project involves the measurement of several aspects of song complexity in a colour-ringed population, and the comparison of these characteristics with the mating success of the different males. DNA fingerprinting will be used to assess the extra-pair paternity.