Pale-breasted Spinetail (Synallaxis albescens) Science Article 1
I recorded and analyzed vocalizations of Synallaxis albescens from three populations in Venezuela,two continental and one island, to assess the extent of geographic variation for a species of the familyFumariidae. Previous work on geographic variation in suboscines has focused on species of the Tyrannidae. Ialso tested the sound environment hypothesis. From nine vocalization characters I created discriminant functionsthat best separated the three populations. I then used classification analyses to determine how well the discriminantfunction models assigned individuals to their home populations. Classification analyses using discriminantfunctions created from first songs of recorded individuals correctly assigned individuals to their home populations74.1% of the time and 66.7% of the time for functions created from arbitrarily chosen sixth songs. The islandpopulation was significantly more variable than either of the continental populations for the first syllable lengthbut not for the frequency-modulated portion of the second syllable. The results demonstrate that geographicvariation exists among populations although a sufficient amount of similarity prevents unequivocal classificationof 5/4 to y3 of individuals to their home populations. The results regarding vocalization variability provide weaksupport for the sound-environment hypothesis.
CATHERINE LINDELL, Wilson Bull., 110(3), 1998, pp. 368-374