Task-dependent workload adjustment of female breeders in a cooperatively breeding fish

Parental investment affects the future survival and reproductive success of breeders. Therefore, breeders should optimize the amount of care they invest into the current offspring. In cooperative breeding systems, the amount of breeders’ parental care is influenced by the behavior of brood-care helpers. Such workload adjustment is expected to depend on the task that needs to be fulfilled. While investment rules of breeders in respect to single tasks are well investigated in many bird and mammal species, little is known about behavioral adjustment of breeders when dealing with multiple tasks. Here, we examined the workload adjustment in multiple tasks of female breeders in the cooperatively breeding fish Neolamprologus obscurus. By combining behavioral observations with helper removal experiments in a wild population, we found that female territory defense and offspring care significantly decreased with increasing helper number. Furthermore, the workload invested in these tasks significa...

亲本投入会影响繁殖者未来的存活与繁殖成功率，因此繁殖者应当优化其对当前子代的抚育投入量。在合作繁殖体系中，繁殖者的亲本抚育投入量会受到育幼帮手行为的调控。此类工作量调整理应取决于需完成的任务类型。尽管诸多鸟类与哺乳类物种中，繁殖者针对单一任务的抚育投入规则已得到充分研究，但目前学界对繁殖者应对多项任务时的行为调整机制仍知之甚少。本研究以合作繁殖性鱼类暗色新亮丽鲷（Neolamprologus obscurus）的雌性繁殖者为研究对象，考察其在多项任务中的工作量调整行为。本研究结合野生种群的行为观察与帮手移除实验，发现雌性繁殖者的领域防御与子代抚育行为会随帮手数量增加而显著降低。此外，针对上述任务投入的工作量显著