Thailand - August 07, 2024

A recent study by Dartmouth researchers sheds light on how social rank influences the eating habits of long-tailed macaques, offering insights into their survival strategies. Published in the journal eLife, the study conducted on Thailand's Koram Island observed distinct behaviors among macaques based on their social status.

Researchers found that dominant and low-ranked macaques tended to consume food quickly, even if it meant ingesting sand along with their meal. In contrast, middle-ranked macaques exhibited a more meticulous approach, often washing their food in the sea to remove sand. This behavior, according to the study, may be linked to long-term health considerations such as preserving tooth enamel and maximizing reproductive success.

Nathaniel Dominy, the study's corresponding author and Charles Hansen Professor of Anthropology at Dartmouth, highlighted the significance of these findings in understanding how animals navigate trade-offs between immediate needs and long-term benefits. The study supports the disposable soma hypothesis, suggesting that animals sometimes prioritize immediate survival and reproduction over longevity.

Amanda Tan, co-corresponding author and assistant professor of anthropology at Durham University, emphasized the role of social structure in shaping behaviors. Tan, who previously observed macaques on Koram Island, noted the rarity of food-washing behavior among primates and its cultural transmission among populations, such as seen among Japanese macaques on Kōjima Island.

The study underscores the complexity of animal behavior and the adaptive strategies that emerge within hierarchical groups. As researchers continue to explore these dynamics, they aim to deepen our understanding of evolutionary pressures and the interplay between social behavior and ecological adaptation.