Laurence R. Gesquiere, a research associate in the department of ecology and evolutionary biology at Princeton, and colleagues report in the journal Science that in five troops of wild baboons in Kenya studied over nine years, alpha males showed very high stress levels, as high as those of the lowest-ranking males.

The stress, they suggested, was probably because of the demands of fighting off challengers and guarding access to fertile females. Beta males, who fought less and had considerably less mate guarding to do, had much lower stress levels. They had fewer mating opportunities than the alphas, but they did get some mating in, more than any lower-ranking males. After all, when the alpha gets in another baboon bar fight, who’s going to take the girl home?