Among people, it is common knowledge that privilege is often inherited.
But according to new findings, hyenas also inherit resources and status, and not just their forebears’ genes, from their parents.
These predictions, formalised as the Darwin-Bateman paradigm, have been confirmed across many mammalian species. The study also showed that female hyenas face more competition shaped by the inheritance of social rank across generations. Instead, they were found spending their time following the alpha female, the highest-ranking female hyenas, around. The Darwin-Bateman hypothesis proposes that reproductive inequality is greater among males. That is, between males and females, the males can father more offspring than females and this is why they compete more among themselves for access to mates. In mammals, the females also invest more in each reproductive event than males do — since they bear the physiological costs of pregnancy and lactation — they are more selective about mating. For their study, the researchers studied hyenas belonging to eight resident clans in the Ngorongoro Crater in Tanzania. “This research teaches us that nothing is fixed. Sex roles are not fixed, like how a male or a female should behave; how our society should behave is not fixed by genetics. Only social processes can actually change society in a meaningful way. The researchers are now exploring whether similar patterns of socially inherited reproductive inequality occur in other animal species. High-ranking females may invest more in daughters to pass on their privileged position while lower-ranking females may favour sons, so they can leave the clan and reproduce elsewhere, Ms.
Because they are bigger or stronger but because they have larger networks of social alliances, scientists at the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in Berlin and the Institute of Evolutionary Science of Montpellier have found that in spotted hyenas, females dominate males not. Their work spanned 29 years of data, eight generations, and 2,743 wild spotted hyenas.
Marta Mosna, the lead author of the study and a researcher at Leibniz-IZW and the Ngorongoro Hyena Project, observed during her field visit in Africa that “male hyenas do not compete so much with each other”. They have said they also want to investigate whether female hyenas invest differently in sons and daughters depending on their social rank. Mosna said. “This study has broad implications for how we understand animal societies: social structures can transmit advantages across generations and thereby shape competition, inequality, and evolutionary outcomes,” Amiyaal Ilany of Tel Aviv University said.
