摘要

Alloparents contribute to offspring care and alleviate the workload of breeders. The help provided varies with the age and/or experience of helpers, but it is not known whether breeders vary their investment based on the age of helpers by adjusting the parental care they provide. We studied the alloparental care provided by juvenile and subadult philopatric daughters in biparental African striped mice Rhabdomys pumilio with and without the mother as a measure of alleviation of maternal workload. We showed in a previous study that alleviation of maternal workload directly affects the development of paternal care in their sons, so we studied the expression of paternal care in young males raised by helpers as a proxy of the long-term consequences of helping. Both juvenile and subadult daughters provided care but the level of alloparental care and concomitant alleviation of maternal care was age-dependent. In the absence of the mother, juvenile daughters provided just 6% of care compared with 24% of subadult daughters. Sons raised by mothers and juvenile helpers displayed the expected exaggerated levels of care also observed when mothers raise litters on their own. While our results show the direct value of subadult daughters, juvenile daughters could contribute indirectly (e.g. nest maintenance) to alleviating maternal workload. The development of paternal care indicates that mothers do distinguish between the care provided by different aged helpers. Overall, the type of alloparental care provided by female striped mice is expected to change over their lifetimes, resulting in increased inclusive fitness through caring for siblings and acquisition of parenting skills.

  • 出版日期2014-1