parity reproductive success social networks social bonds animal personality fitness
In social mammals, social integration is generally assumed to improve females' reproductive success. Most species demonstrating this relationship exhibit complex forms of social bonds and interactions. However, female eastern grey kangaroos ( Macropus giganteus ) exhibit differentiated social relationships, yet do not appear to cooperate directly. It is unclear what the fitness consequences of such sociability could be in species that do not exhibit obvious forms of cooperation. Using 4 years of life history, spatial and social data from a wild population of approximately 200 individually recognizable female eastern grey kangaroos, we tested whether higher levels of sociability are associated with greater reproductive success. Contrary to expectations, we found that the size of a female's social network, her numbers of preferential associations with other females and her group sizes all negatively influenced her reproductive success. These factors influenced the survival of dependent young that had left the pouch rather than those that were still in the pouch. We also show that primiparous females (first-time breeders) were less likely to have surviving young. Our findings suggest that social bonds are not always beneficial for reproductive success in group-living species, and that female kangaroos may experience trade-offs between successfully rearing young and maintaining affiliative relationships.
Details
Title
Higher sociability leads to lower reproductive success in female kangaroos
Authors
C. S Menz (Author) - The University of Queensland
A. J Carter (Author) - University College London
E. C Best (Author) - The University of Queensland
N. J Freeman (Author) - The University of Queensland
Ross Dwyer (Author) - University of the Sunshine Coast, Queensland, School of Science and Engineering - Legacy
S. P Blomberg (Author) - The University of Queensland
A. W Goldizen (Author) - The University of Queensland