Most of the diversity of in the mating systems of birds and other animals come at higher taxonomic levels, such as across orders. Although divergent selective pressures should lead to animal mating systems that diverge sharply from those of close relatives, opportunities to examine the importance of such processes are scarce. We addressed this issue using the Araripe manakin (Antilophia bokermanni), a species endemic to a forest enclave surrounded by xeric shrublands in Brazil. Most manakins exhibit polygynous lekking mating systems that lack territoriality but exhibit strong sexual selection. In sharp contrast, we found that male Araripe manakins defended exclusive territories, and females nested within male territories. However, territoriality and offspring paternity were dissociated: males did not sire most young within their territories, and nonterritorial males sired numerous nestlings. Moreover, female polyandry was widespread, with most broods exhibiting mixed paternity. Apparently, territories in this species function differently from both lekking arenas and resource-based territories of monogamous species. The unexpected territoriality of Araripe manakins and its dissociation from paternity is a unique evolutionary development within the manakin clade. Collectively, our findings underscore how divergences in mating systems might evolve based on selective pressures from novel environmental contexts.  

Field data were collected in the Araripe plateau in northeastern Brazil. Birds were mist-netted and morphological measurements were taken. Blood samples were collected from all captured adults. Nests were found and monitored, and when nestlings hatched, blood samples were collected. We extracted DNA from blood samples using a standard extraction protocol (QIAGEN®) and sexed adults and nestlings with the primer set 2550F/2718R. We genotyped samples from chicks using 15 polymorphic microsatellite markers and ran paternity analysis in Cervus 3.0.0. Details are presented in the electronic supplementary material with the manuscript.