In spotted hyena societies, inherited social networks — passed from mothers to offspring — are essential to hyena life and survival, according to a new study.
While the structure of animal social networks plays an important role in all social processes as well as health, survival, and reproductive success, the general mechanisms that determine social structure in the wild remain unknown.
One proposed model, termed social inheritance, suggests that an offspring’s social affiliations tend to resemble those of their parents, particularly those of the mother. Previous research has indicated that these inherited social networks may influence social structure across generations in multiple species.
Here, Amiyaal Ilany and colleagues evaluate the role of social inheritance in spotted hyena society, which is female-dominated and highly structured. Combining social network analysis and a transgenerational dataset comprised of 73,767 social observations among a population of wild hyenas collected over 27 years, Ilany et al. found that that the social relationships of juvenile hyenas are similar to those of their mothers and that the degree of similarity increases with the mother’s social rank.
What’s more, the results show that the strength of the maternal relationship affects social inheritance and is also positively correlated with the long-term survival for both mother and offspring.
According to the authors, the findings suggest that selection for social inheritance might play an essential role in shaping hyena social behavior and the fitness of individual hyenas.
“Future work should seek to examine how widely specific social relationships are inherited in a range of population structures and what implications this has for the rate of evolution of the many processes that depend on social network structure,” write Josh Firth and Ben Sheldon in a related Perspective.
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Reference: “Rank-dependent social inheritance determines social network structure in spotted hyenas” by Amiyaal Ilany, Kay E. Holekamp and Erol Akçay, 16 July 2021, Science.