Advertisement Call Variation in the Golden Rocket Frog (Anomaloglossus beebei): Evidence for Individual Distinctiveness

Individual distinctiveness in acoustic signals can allow receivers to respond appropriately to different individuals. The aim of this research was to examine signal variation and to investigate the relative importance of different acoustic properties for coding individual distinctiveness in the advertisement calls of male golden rocket frogs (Anomaloglossus beebei). We examined patterns of within-individual and among-individual variability in 760 advertisement calls of 40 males as well as repeatability in 16 additional males that were recorded on two different occasions. We examined eight call properties, and all properties exhibited significant among-individual variation and moderate to high repeatability across days. We employed discriminant function analysis to examine individual distinctiveness statistically. These analyses assigned 79% of calls to the correct individual. Fine temporal properties, including pulse duration, pulse rate, and pulse interval, as well as the spectral property of dominant frequency, contributed most toward discrimination among individuals. These results indicate that individual male golden rocket frogs can be distinguished statistically by their advertisement calls. We use these findings to evaluate results of previous playback studies in A. beebei and to generate testable predictions regarding the potential for specific call properties to function in mate selection and social recognition.