Abstract

LOMBARDI, Celia María  and  FARINA, Walter. Joining a group decision by captive saffron finches (Sicalis flaveola) in competitive situations. Rev. etol. [online]. 2004, vol.6, n.2, pp. 73-78. ISSN 1517-2805.

Visual and auditory cues play an important role in promoting behavioral synchronization. Captive saffron finches (Sicalis flaveola, Passeriformes, Emberizidae) confronted with a steady size of food patch, fly to the ground more often and remain longer on it when bird density is higher. The observed effect, independently of being triggered by sensory cues resulting from more birds, may be a consequence of the increased competitiveness required by the situation. In this paper we have tested this hypothesis. We held birds in a steady group size and describe their decision to join a group at the ground at successive intervals, when variable food patch size was offered. We found that the smallest food patch size promoted the largest group size of birds on the ground. Analyses of the time domain showed that when the smallest food patch size was available, decisions to join the group on the ground were made at shorter time intervals. Apparently, birds are capable of adjusting their decisions according to the perceived competitiveness of the situation.

Keywords : Decision; Time series; Social facilitation; Competitive interaction; Finches; Sicalis flaveola.

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