Dataset information and code used in Extra nestlings that are condemned-to-die increase reproductive success in hoopoes

We discuss the potential adaptive functions of laying optimistic clutch sizes that hatch asynchronously in hoopoes, a bird species with frequent sibling cannibalism. The production of extra eggs could serve as insurance against hatching failures, while the surplus hatchlings can be used as food and increase the probability of survival of their older siblings. Two experiments were conducted to explore the adaptative functions of producing extra offspring, one involving food supplementation during the egg-laying period, and the other manipulating brood size and hatching span. Results showed that females with extra food laid one more egg on average and that adding an extra egg that hatched the last increased sibling cannibalism and fledging success. These findings suggest that hoopoes are able to recover part of the cost of producing large clutches by consuming surplus chicks.