LIPAUGUS · Control of reproductive behaviors in an equatorial sub-oscine bird: Implication for biodiversity studies

Although birds are the best studied vertebrate group, most studied species are endemic to the temperate zones while about half of all bird species life in the tropics. Further, among the tropical species many belong to the so-called sub-oscine passerines while the temperate zones are dominated by their sister group, the oscines or songbirds. The knowledge of the biodiversity of reproduction mechanisms of tropical species including the sub-oscines is essential to understand the generality of behavioral mechanisms derived from temperate zone species and required for conservation efforts. In an interdisciplinary longitudinal approach we study the reproductive behavior of a prominent tropical bird, the sub-oscine Lipaugus vociferans (screaming piha), the voice of the Amazon that inhabits most lowland forest of the Amazon basin. In the obstructed environment of the raining forest, reproductive success depends on vocalization. Male pihas sing in a chorus to achieve group precision required to attract females. Despite such complicated singing, the songs of the screaming piha are thought to be innate since this species belongs to the sub-oscines while the songs of related songbirds are learned. In relation, sub-oscines are thought to lack particular hormone-sensitive brain region that control vocal learning and control the seasonal singing of temperate songbirds. However, not only requires the chorus singing of the piha precision, their vocal performance is clearly seasonal. The study of reproductive behaviors such as vocalizations in a sub-oscine species near the equator delivers insights in (1) the environmental Zeitgeber(s) that synchronize reproductive behaviors in the tropics, (2) the endocrine factors that translate the external Zeitgeber into neuroendocrine mechanisms that facilitate vocal courtship and (3) the mechanisms of vocal learning of sub-oscines.