Resposta comportamental a playback de vizinhos e estranhos em Embernagra longicauda (aves, passeriformes)

Abstract

Territorial animals tend to respond more strongly to strangers than to territorial neighbors. They may learn the signals of each neighbor, which is defined as neighbor-stranger discrimination or "dear enemy" effect. The aim of this study was to check whether territorial Embernagra longicauda discriminate neighbors from strangers. The study was conducted in the Serra do Cipó National Park between July and October 2015, using six previously marked pairs with defined territory. Experiments using song playbacks of the nearest neighbor and of strangers were applied between 6-11 in the morning. Each trial consisted of playing back territorial song from the center of the territory for 10 minutes with 20-minute interval between them and evaluating the behaviors that individuals expressed after each stimulus. The assessed behaviors were: number of songs, latency, approach distance, flights around and use of perches. It was run a paired t test to compare the number of songs, approach distance and flights around between the two types of treatment. It was made a chi square test to evaluate use of perches and survival analysis to compare response time. There was no significant difference for any evaluated behaviors; it is not possible to detect the neighbor-stranger discrimination in Embernagra longicauda. This species is the same as their territorial neighbors and strangers, this pattern is different from that found in Emberizidae family species that are phylogenetically close the Thraupidae family, which belongs E. longicauda, but there is no evidence whether this behavior has phylogenetic effect or ecological-behavioral in that group. The fact that the experiments were conducted in the center of the territories may explain the aggressiveness of individuals, as neighbors may have lower level of threat near the territorial boundaries, but have the same level of threat that a stranger to invade the territory, as simulated in this study.