Song preferences in female Java Sparrows: Familiarity or Complexity?

Songs play an important role in mate choice for many bird species. Females of some species prefer mates with song characteristics such as complexity, or with specific temporal or note features. In some species, females also prefer familiar songs, or songs that are acoustically similar to those of their fathers. These different aspects of songs may provide distinct information about the birds that produced those songs. For example, perceived familiarity may be a signal of local adaptation, locally relevant information or learned behaviours, or genetic compatibility, while song complexity may be a signal of overall genetic quality or ability to provide parental care. As a result, multiple axes of variation could influence female song preferences. We examined female preference for song familiarity and complexity using the Java sparrow (Lonchura oryzivora) as a model species. Females were presented with two pairs of song stimuli. In one pair one song was from the females father or from a social relative with an acoustically similar song and the other was unfamiliar. In the other pair the songs differed in two aspects of complexity: note repertoire and linearity. Females preferred their fathers songs over unfamiliar songs, but we did not find strong evidence that females generalized this preference to other socially related individuals. Females also preferred complex songs, specifically those with larger note repertoires and lower linearity. Our results suggest that female song preference in Java sparrows is multi-faceted, and females may obtain multiple kinds of information from male song.