Guttural calls of Blue-fronted Amazons: Structure, contex,t and their possible role in short-range communication.

FERNANDEZ JURICIC, E.; MARTELLA, M.B.

WILSON JOURNAL OF ORNITHOLOGY

WILSON ORNITHOLOGICAL SOC

Año: 2000 p. 35 - 43

1559-4491

Structural variability of guttural calls of Blue-fronted Amazons (Amazona aestiva) was examined and the contexts in which they were given discussed relative to the role these vocalizations might play in short-range communication. Recordings were obtained at the Chancani Reserve, C6rdoba, Argentina, during breeding and non-breeding seasons. Guttural calls were given year round, but were more common during the non-breeding season when most of the individuals were interacting in flocks. Gutturals were detected when perched parrots contacted each other, during take-offs, landings, complex flock flying maneuvers, and feeding sessions. Guttural calls were subdivided into four types based on structure, but none of these types could be clearly assigned to a specific context. Structural variation in guttural calls was continuous rather than discrete, with the variability within and among individuals being similar. Many guttural notes graded into one another and were combined with other vocalizations. Gutturals were brief, had sudden onset, wide bandwidth, and low intensity. Gutturals could be regarded as short-range calls because of their large structural variability (fewer restrictions of sound attenuation and degradation) and low intensity (decreased attraction of predators). They were also produced by large flocks, probably as a means of maintaining contact, enhancing group spacing, and coordinating movements of individuals.