Male Saccopteryx bilineata produces complex audible vocalizations during the day while defending roost territories within the buttress cavities of trees. To determine the amount of variability in the vocal repertoire and how this variation is apportioned among geographic locations and individuals within colonies, we recorded daytime vocalizations of male S. bilineata at 4 colonies on the island of Trinidad. Using visual discrimination, we identified 21 simple syllables and 62 composite syllables produced by males on the island. Using syllable counts for each colony and a nonlinear regression model, we found that 1 colony had an estimated repertoire size much larger than the others. Using 1st syllable of a common call type, we found several acoustic characteristics that showed significant individual variation, and 1 of those features also exhibited differences between colonies that were located in close proximity and colonies that were geographically separated. The vocal repertoire of male S. bilineata is variable, with considerable potential for information transfer.