Drivers of alloparental provisioning of fledglings in a colonially breeding bird

Abstract Reproduction is costly. Despite this, evidence suggests that parents sometimes feed unrelated offspring. Several hypotheses could explain this puzzling phenomenon. Adults offspring are 1) of their close social associates to facilitate these juveniles’ integration into network (the inheritance hypothesis), 2) potential extrapair offspring, 3) at a similar developmental stage as own, 4) coercing feeding by begging, or 5) less-developed (to enhance survival, which benefit the adult its offspring; group augmentation hypothesis). Colonial breeders ideal for investigating relative importance because often kept in crèches where adults can exhibit allofeeding. Using automated monitoring replicated captive zebra finch (Taeniopygia guttata) colonies, we found while selectively fed own they also consistently (32.48% events). Social relationships among prior breeding did not predict allofeeding, nor was allofeeding directed toward genetic Instead, with more-developed preferentially non-offspring over and tendency explained differences begging behavior. Our study consistent augmentation, potentially benefiting through colony maintenance increased survival.