How helpers help themselves: alloparental care in the African striped mouse — ASN Events

How helpers help themselves: alloparental care in the African striped mouse (#516)

Tasmin L Rymer 1 2 , Neville Pillay 2
  1. College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland, Australia
  2. School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, Gauteng, South Africa
Alloparental care includes all behaviours performed by a non-parent that benefit non-descendent offspring. Alloparental care occurs in a variety of taxa and the functional benefits to both the helper and the receiving offspring have been relatively well studied. Alloparental care varies with the age and/or experience of the helper, showing phenotypic plasticity of helping. However, it is unknown whether parents respond to these developmental changes of helpers and little is known about whether alloparents develop and enhance other behavioural phenotypes as a consequence of helping. Our current research focuses on these issues in the African striped mouse Rhabdomys pumilio from the Succulent Karoo of South Africa. Rhabdomys pumilio is a facultatively group-living species, in which offspring overwinter in the group nest and provide alloparental care to their younger siblings. Our research has provided two sets of important findings. Firstly, daughters alter the level of alloparental care provided as they age, which is independent of their experience of providing care. Sub-adult daughter helpers alleviate their mother’s workload, which impacts on the development of paternal care in their younger brothers which they help raise. In contrast, the contribution of juvenile philopatric daughters to alloparental care is marginal because they do not alleviate maternal workload and do not appear to contribute to their younger siblings’ behavioural development. Secondly, female alloparents show enhanced spatial memory, reduced anxiety in novel environments and better competitive ability compared to non-alloparents. This suggests that, by providing alloparental care, female alloparents can improve their own ability to locate resources while improving their own parental skills. Our findings indicate that alloparental care leads to dynamic responses by parents and potentially provides direct fitness benefits for alloparents.