The Cost of Being King: Alpha Baboons Trade Power for Survival

By Dr. Chinta SidharthanReviewed by Lily Ramsey, LLMFeb 3 2025

In the wild, dominance comes at a cost, and new research on male baboons reveals just how steep that price can be. A recent study on wild baboons in Kenya’s Amboseli ecosystem, published in the Proceedings of the Royal Society B: Biological Sciences, has uncovered that alpha males face significant energetic demands, as reflected in their hormone levels.

A team of researchers from the United States and Kenya measured thyroid and glucocorticoid levels in dominant and subordinate males and discovered that while alpha males hold the most mating power, they also experience sustained energetic costs.

This study sheds light on the trade-offs of social status in the animal kingdom, with implications for understanding stress and leadership in social species.

​​​​​​​Study: Energetic costs of social dominance in wild male baboons. Image Credit: miroslav chytil/Shutterstock.com

Social Dominance

The lives of many animals are organized in numerous layers of social dominance, which influence factors such as access to resources, mating opportunities, and overall survival. In primates, especially baboons, dominance hierarchies shape daily interactions and long-term success.

Previous studies have shown that lower-ranking animals often experience high stress due to social instability and resource competition. However, research on social groups of animals such as primates has revealed a more complex picture — dominant individuals often endure greater physiological stress than subordinates.

One of the major challenges in studying this phenomenon has been distinguishing between different types of stress.

While glucocorticoid hormones indicate overall stress levels, they respond to both psychosocial and energetic demands, making it difficult to isolate the true causes of stress. In contrast, thyroid hormones primarily reflect metabolic activity, offering a clearer picture of energy expenditure.

Current Study

In the present study, the researchers analyzed both hormone types to determine whether dominant male baboons experience greater energetic costs than their lower-ranking counterparts. They studied a population of wild baboons in Kenya’s Amboseli Basin, which is a long-term field site where individual animals are identified and closely monitored.

The team collected over 4,500 fecal samples from 204 adult male baboons between 2004 and 2018. These samples were analyzed for two key hormones: fecal glucocorticoids, which indicate stress, and fecal triiodothyronine, a marker of metabolic activity and energy expenditure.

Radioimmunoassay was used to measure the fecal glucocorticoid levels, while triiodothyronine concentrations were analyzed with an iodine-based assay. The researchers also recorded behavioral data, including aggressive interactions and time spent in mate-guarding or consortship of fertile females. Dominance ranks were determined through observations of social interactions, with alpha status assigned to the highest-ranking male each month.

Environmental factors such as rainfall, temperature, and seasonality were also included in the analysis, as these could influence hormone levels. The statistical models accounted for variables such as male age, group size, and hierarchy stability.

The study aimed to determine whether alpha males exhibit higher energetic costs compared to lower-ranking individuals and whether specific behaviors, such as aggression and mate-guarding, contribute to these costs.

Key Findings

The study found that alpha males experience significantly higher energetic costs than their lower-ranking counterparts.

Specifically, they had lower levels of triiodothyronine, indicating sustained metabolic stress, and elevated glucocorticoid concentrations, reflecting chronic stress exposure. Cumulatively, this suggested that maintaining dominance comes with persistent physiological demands.

One key driver of this energetic cost was mate-guarding behavior. Alpha males spent more time guarding fertile females, a behavior that restricted their feeding opportunities and increased their overall energy expenditure. The study revealed that males who spent more time in mate-guarding exhibited higher fecal glucocorticoid levels, confirming the link between reproductive effort and stress.

Interestingly, low-ranking males displayed higher triiodothyronine levels, indicating they were under less energetic strain despite experiencing social stress. Unlike alpha males, their stress markers were not linked to high energy expenditure but rather to psychosocial factors, such as avoiding conflicts with dominant males.

The results of the study challenged the assumption that dominant individuals always have lower stress levels due to their control over resources. Instead, the study highlights a key trade-off that occurs in the wild — while alpha males enjoy reproductive advantages, they also endure heightened energetic and physiological burdens.

These findings provided new insights into the costs of leadership, suggesting that dominance, while advantageous, may accelerate aging and reduce lifespan.

Conclusions

In summary, the study revealed that being at the top of a social hierarchy comes with significant energy costs. While alpha male baboons secure the best mating opportunities, they also endure chronic stress and metabolic strain.

These findings challenged the notion that dominance equates to an easy life, and provided valuable insights into the trade-offs of leadership in social species, including potential parallels in human social and professional hierarchies.