A PERFORMANCE CONSTRAINT ON THE EVOLUTION OF TRILLED VOCALIZATIONS IN A SONGBIRD FAMILY (PASSERIFORMES: EMBERIZIDAE)

摘要: Behavioral evolution can be influenced by constraints, for example, of phylogeny and performance. In this paper I describe a pattern in the birdsongs that may reflect constraint on vocal Trilled vocalizations from 34 species songbirds (Passeriformes: Emberizidae) were analyzed. Two acoustic variables, trill rate frequency bandwidth, measured different types. most species, maximal values bandwidth found to decrease with increasing rates. Further, trills low rates exhibited wide variance high only narrow bandwidths. The bounded nature suggests performance constraints have limited evolutionary diversification trills. particular, explore role associated tract modulations during song production evolution. Identification enhance our ability explain particular patterns