The evolution of paternity and paternal care in birds

Paternity has been hypothesized to be related to the evolution of paternal care because (1) there should be selection for males not to invest in brood s with an uncertain parentage, or (2) male extrapair activity is traded aga inst paternal care. We used interspecific comparisons to discriminate betwe en these alternatives. Male participation in three kinds of parental care ( nest building, incubation, provisioning of offspring) increased with high p aternity in their own nests, Male parental activities at some stages of the breeding cycle were significantly correlated. A multivariate analysis taki ng this intercorrelation between different components of care and potential ly confounding variables such as precociality, polyandry, and sexual dichro matism into account revealed that paternity was significantly positively re lated to offspring provisioning, while male participation in the other comp onents of parental care did not explain a significant amount of interspecif ic variation in paternity. Analyses of evolutionary transitions between dif ferent dichotomized states of paternity and paternal care provided no clear conclusions concerning evolutionary scenarios. However, theoretical argume nts and the results of the contrast analyses suggest that mate provisioning of offspring evolved in response to paternity.