Análise do desenvolvimento das interações sociais do Tangará Chiroxiphia caudata (aves, Pipridae)

Abstract

The blue manakin Chiroxiphia caudata is a bird of the Pipridae family with distribution in the Atlantic Forests of Brazil, Argentina and Paraguay. Males have a lekking polygynous system, aggregating in certain places that females visit to copulate. As soon as the female is at the lek, the courtship displays begin. There is a linear dominance hierarchy between adult males, in which only the dominant, or alpha, copulates with the female. The objective of this study was to examine the development of social interactions of the blue manakin.The study was conducted in two deciduous forest areas in Santa Maria, RS. Leks were observed from October 2009 to February 2010. Results are presented in two chapters. The first one reports the hierarchy ascension of adult males in the absence of the dominant male. In one lek there was a subordinated male (gamma), which participated in another lek as an alpha male. When the dominant male (alpha) left the main lek, the beta was expected to take its place. Nevertheless, it was the gamma that actually did. Thus, I propose a system of main and secondary leks to explain the structural differences of the observed leks. The second chapter reports the use of space by different adult males according to their hierarchies as well as by young males. Adult males presented home ranges of similar size and that overlap according to the hierarchical level of individuals. However, it was found a preference for certain perches according to the status of the male. Yet the distances traveled were similar.