Paternal behaviour in a socially monogamous but sexually promiscuous passerine bird

Abstract

We documented parental behaviour and paternity of eastern kingbirds (Tyrannus tyrannus) to test the predictions that paternal care would decline with increasing loss of paternity, increasing nesting density (a proxy for probability of paternity loss), male quality, and number of fertile females available in the population. Extra-pair young were found in 58% of 45 nests for which behaviour was recorded and a higher proportion of young were extra-pair as nesting density increased. Male feeding rate declined with increasing nesting density and male quality, but neither feeding rate nor a composite measure of paternal behaviour varied with number of fertile females or paternity. Although alternative explanations exist, one interpretation of the reduced paternal care at high nesting density was that it was a response to perceived threats of paternity loss. The ultimate basis for the lower paternal effort of higher quality males is unclear but we discuss several possible explanations.

Population decline of a long‐distance migratory passerine at the edge of its range: nest predation, nest replacement and immigration

“…Socially monogamous pair bonds persist through the season (Murphy 1996). Females alone incubate eggs (15 days) and brood young, but both sexes feed young at equal rates at MNWR (Chutter et al 2016). Typical clutch size is 3 or 4 eggs (range = 2-5) and young fledge at 16-17 days of age (hatching = 1).…”

Antilophia bokermanni (Aves: Pipridae) : parâmetros reprodutivos, sistema de acasalamento social e genético e o papel da seleção sexual

“…A comprovação de que machos não auxiliam em nenhuma etapa do cuidado parental, incita um questionamento sobre a atual classificação do sistema de acasalamento de A. bokermanni, considerada socialmente monogâmica. Em espécies socialmente monogâmicas é comum que a fêmea receba auxílio do macho, seja no cuidado com a prole ou com alimentação trazida pelo macho para a fêmea durante a incubação, por exemplo , Chutter et al 2016.…”