In the savannas of Kenya, where the sun beats down on the golden grasses and acacia trees, male baboons live in a world of constant competition. To rise to the top of the social ladder is to gain access to mates, food, and status. But a new study reveals that this coveted position comes at a steep cost. Alpha male baboons, it turns out, pay a heavy price for their dominance — one that may shorten their lives.
For decades, scientists have been fascinated by the social hierarchies of baboons. But while much attention has been paid to the benefits of being an alpha male, less is known about the toll it takes on their bodies. A team of researchers led by Laurence R. Gesquiere from Duke University set out to uncover the hidden costs of dominance by studying the hormonal profiles of wild male baboons in Kenya’s Amboseli Basin.
They found that the alpha baboon stress hormones, known as glucocorticoids, soar higher than those of their lower-ranking peers. What was particularly intriguing is that it wasn’t the battles they fought with other males to maintain their status that stressed out the alphas.
What was most consuming was guarding their mates so fiercely.
It’s Tough at The Top
Susan Alberts, a biologist at Duke University and a leading researcher on the Amboseli Baboon Research Project, has spent years studying these primates. “Being alpha really has energy consequences,” she said in a press release.
Baboon alpha males spend an extraordinary amount of time shadowing fertile females, ensuring no rivals get too close. This behavior, known as “mate guarding,” demands constant vigilance. They follow females from one spot to another, often abandoning meals to keep up. “They’re constantly interrupted,” Alberts explained. “The female gets up and walks away, and they have to abandon [the food].”
Over time, this relentless effort drains their energy and raises their stress levels. To learn more about the darker side of being the head of the troop, researchers focused on two key hormones: glucocorticoids (often referred to as stress hormones) and thyroid hormones, which regulate metabolism. By analyzing fecal samples from over 200 male baboons collected over 14 years, the team was able to track how these hormones fluctuated with social rank.
What they found was striking. Alpha males had significantly higher levels of glucocorticoids (6% more) than other males, indicating they were under more stress. But the real surprise came when they looked at thyroid hormones. Alpha males had lower levels of these hormones, suggesting their bodies were conserving energy.
This combination — high stress and low metabolic activity — paints a picture of males who are constantly on edge, burning through their energy reserves to maintain their status. “They’re essentially running on empty,” Gesquiere explains.
“Alpha males experience consistent exposure to energetic challenges to a greater extent than other males,” the researchers wrote in their study published in the Proceedings of the Royal Society B.
What’s surprising is that this stress isn’t fueled by the alpha males’ aggressive behavior. Whether they’re threatening rivals or asserting dominance, these actions don’t significantly impact their hormone levels. This contrasts with other species, such as chimpanzees, where aggression is a major source of stress and energy expenditure. Instead, the real energy drain comes from their relentless efforts to monopolize fertile females.
The Mating Game: A Costly Affair
For alpha male baboons, reproduction is a high-stakes game. To ensure they father the next generation, they must closely monitor females during their fertile periods, following them for days at a time. This constant vigilance leaves little room for rest.
The more time alpha males spend guarding mates, the higher their stress hormones rise and the more their energy reserves deplete. Over time, these demands can have serious consequences. Previous studies have shown that alpha males age faster and live shorter lives than their lower-ranking counterparts.
But that doesn’t mean being a baboon pleb is always rainbows and butterflies. While alpha males bore the brunt of the energetic costs, low-ranking males had their own struggles. They showed higher levels of thyroid hormones, suggesting they were less energetically stressed. But their glucocorticoid levels were similar to those of high-ranking males, indicating they faced significant psychosocial stress — likely from being at the bottom of the pecking order.
“Low-ranking males, while being less energetically challenged than high-ranking males, are probably exposed to more psychosocial stressors,” the researchers noted.
This finding challenges the traditional view that low-ranking animals are always the most stressed. Instead, it suggests that different ranks face different kinds of challenges. It’s tough being a male baboon — period.
One of the most intriguing findings of the study was the role of consortships — the time males spend guarding fertile females. The researchers expected that males who engaged in more consortships would show signs of energy depletion, with lower thyroid hormone levels. But the opposite was true. Males who spent more time in consortships had higher thyroid hormone levels, suggesting they were in better energetic condition.
This paradox may be explained by the fact that only males with sufficient energy reserves can afford to engage in consortships. In other words, consortships are a luxury that only the most energetically fit males can afford.
The Bigger Picture
While baboon hierarchies are far simpler than human social structures, the findings offer intriguing insights into the costs of leadership. In humans, stress is often tied to the pressures of work, relationships, and societal expectations. But as Gesquiere points out, “We belong to multiple communities throughout our lives, each with its own social dynamics.”
For baboons, however, the stakes are clear. “Stress definitely has long-term consequences,” Gesquiere says. The alpha male’s role, while prestigious, comes at a price — one that underscores the delicate balance between power and well-being.
As the sun sets over the Kenyan savanna, the alpha male baboon continues his watchful patrol. His dominance is unquestioned, but so too is the toll it takes. In the end, even the strongest must grapple with the weight of their crown.
