Song Characteristics and Variation in a Population of Bananaquits on Puerto Rico

Abstract

Bananaquits (Coereba flaveola) in a high density island population with small permanent territories, numerous intraspecific interactions, and polygyny, showed many of the song characteristics expected for species with these life history traits. These song characteristics included high singing rates, relatively large song repertoires (120-340 song types per male); predominance of rare song types; and sequence of song types presented with a pattern approaching immediate variety. Note arrangement within a song was indeterminate and nonrandom; the probabilities of occurrence of a specific note type depended on at least the immediately preceding note. Nine males uttered 10 different note types, of which 9 were shared by all; nonetheless, few song types were shared by neighbors. Different song types were produced primarily by the addition or deletion of notes at the end of a song, whereas the introductory notes were less variable. Males differed from each other in note usage and song types, but produced similar levels of song variation. No consistent relationship was found between singing continuity and song versatility. Songs of two juveniles (4-5 months), a yearling (10-11 months), and older (>1 yr) males indicated that song variation declines with age until at least the second year, when the sequence of notes in a song becomes more predictable.