INVESTIGADORES
KOPUCHIAN Cecilia
congresos y reuniones científicas
Título:
Intra and inter-specific vocal variation in three species of Grosbeaks (Passeriformes: Cardinalini) and its relationship with body mass
Autor/es:
GARCÍA, NATALIA CRISTINA; BARREIRA, ANA SOLEDAD; KOPUCHIAN, CECILIA; TUBARO, PABLO LUIS
Lugar:
Vancouver
Reunión:
Conferencia; V North American Ornithological Conference; 2012
Resumen:
The negative relationship between song frequencies and body size, first described for birds by Wallschläger in 1980, is well supported by several studies considering a large number of species, but contradicting results were obtained at the intraspecific level. Variation in temporal song traits, on the other side, has been related to the effect of the habitat acoustics on song communication. However, the rate at which notes are produced could also be related to morphological traits that usually correlate with body size, such as bill length or depth. Here, we compared the vocalizations of Cyanoloxia glaucocaerulea, Cyanocompsa brissonii and Cyanocompsacyanoides. Cyanoloxia glaucocaerulea and Cyanocompsa brissonii are sister species, and Cyanocompsa cyanoides is the sister species of this clade. Both Cyanocompsa species are divided into several subspecies, so they provide a good model to describe the variation in song traits in relation to body mass in closely related groups. We analyzed the songs of C. glaucocaerulea, the four subspecies of C. cyanoides and four out of the five subspecies of C. brissonii using the program Raven version 1.3. We measured frequency and time-related variables, and we collected weight data from specimens stored at different museums and also from bibliography. We evaluated the correlation between each song variable and the mean weight of each group. We found significant differences between and within species in both frequency and time-related variables, as well as in body mass. When comparing all the groups together we found that emphasized frequency shows a clear negative correlation with body mass. Note rate and internote interval length also significantly correlated with body mass, the heavier species having lower note rate and longer internote intervals. Even though the differences are small, our results suggest that the negative correlation between frequency and body size stands when comparing closely related groups, at least for the emphasized frequency. The correlation of note rate and internote interval length with body mass that we found suggests that body size could also influence the temporal structure of song, as it was previously found in birds with trilled sequences in their songs, at both the intra and interspecific levels.