Alpha males are surprisingly rare among primates – new research

Is it true that male animals are dominant over females? Previous studies have often found male-biased power in primates and other mammals.

- BY LOUISE GENTLE Principal Lecturer in Wildlife Conservation, Nottingham Trent University

A new study, investigating physical encounters between members of the same species in 121 primates (around a quarter of all primate species) found that half of all aggressive contests were between males and females. But males won these contests in only 17% of primate populations, with females dominating in 13% — making it almost as likely for females to dominate males.

The remaining 70% of primate populations showed no clear-cut dominance of one sex over the other. This study may have shown different results to previous research because it assessed individual contests rather than categorising species based on their social structure and physical attributes.

The new study found male dominance, where males have a greater ability to influence the behaviour of the opposite sex, to be prevalent in primate species where the males are much larger than the females. This enables males to gain dominance through physical force or coercion. It was also widespread in species where males have weapons and mate with lots of females.

This is typical of African and Asian monkeys and the great apes, such as gorillas. Weighing in at around 200kg, a silverback male can be twice the size of the females within his troop. Male gorillas also have large canine teeth that can seriously injure or even kill other gorillas.

Male dominance often twins with weapons throughout the animal kingdom, — horns, antlers, claws or tusks. The largest antlers ever known were those of the now extinct Irish elk, spanning lengths up to 3.5m.

Female dominance