When it comes to gibraltar’s monkeys eat mud ‘to avoid upset stomachs from tourist junk food’, monkeys on the Rock of Gibraltar are adapting to an unusual diet, consuming soil to counteract stomach issues caused by the junk food they receive from tourists. This behavior, known scientifically as geophagy, has been observed among the Barbary macaques that inhabit the territory. Researchers attribute this phenomenon to the increasing amount of unhealthy snacks the monkeys encounter, especially during peak tourist seasons.
Approximately 230 Barbary macaques live on Gibraltar, divided into eight distinct groups. Though local authorities provide a daily diet of fruits, vegetables, and seeds, tourists frequently feed them a variety of snacks, including chips, chocolate bars, and ice cream. The macaques that had the most interaction with tourists were found to consume the highest amounts of soil, particularly during the holiday season when tourist numbers surge. Originally reported by The Guardian.
Understanding Gibraltar’s Monkeys Eat Mud ‘to Avoid Upset Stomachs From Tourist Junk Food’
The intentional eating of soil is a behavior that has piqued the interest of scientists, particularly in the context of how it relates to the macaques' digestive health. Dr. Sylvain Lemoine, a primate behavioral ecologist at the University of Cambridge, suggests that the monkeys may be instinctively trying to rebalance their gut microbiomes, which can be disrupted by the fatty, sugary, and salty snacks they often consume.
Dr. Lemoine notes, "We think that eating this junk food disrupts the composition of the microbiome and we know that bacteria and minerals in soil can help recompose the microbiome and alleviate the negative effects." Interestingly, the only group of macaques not observed eating soil was one that is isolated from tourists, indicating a direct link between human interaction and this unusual dietary choice.
The Impact of Tourist Feeding on Monkey Diets
Over the course of research conducted between summer 2022 and spring 2024, it was found that nearly 20% of the macaques' total food intake consisted of junk food sourced from tourists. Those macaques residing near the top of the Rock, a popular tourist destination, were more than twice as likely to indulge in junk food compared to others, correlating with their higher soil consumption.
Dr. Lemoine emphasized the variety of junk food offered to the monkeys, ranging from salted peanuts and chocolate bars to ice cream. He commented, "There's a lot of ice cream. They love Magnums and Cornettos. What they don't like very much is sorbet." This abundance of high-calorie treats appears to have a direct impact on the monkeys' health and behavior, pushing them to seek out soil as a form of dietary counterbalance.
Seasonal Trends in Monkey Behavior
The research also revealed seasonal trends in the monkeys' eating habits. During the winter months, when tourist numbers drop significantly, the macaques were found to be 40% less likely to consume junk food and more than 30% less likely to eat soil. This clear correlation suggests that the feeding behavior of tourists plays a critical role in the dietary choices of these monkeys.
In total, the researchers noted 44 instances of soil consumption among the macaques, recording that in three cases, the monkeys consumed soil shortly after being fed high-calorie snacks. Notably, the monkeys seem to prefer different soil types based on their troop, with many opting for the terra rossa, or red clay, prevalent across Gibraltar.
Geophagy: A Coping Mechanism?
Drawing comparisons to human behavior, it is not uncommon for people in various cultures to consume soil, particularly among pregnant women seeking to alleviate nausea or obtain essential minerals. However, researchers found no significant increase in soil-eating among pregnant or lactating macaques, suggesting that their geophagy is not driven by a nutritional deficiency but rather as a way to buffer their digestive systems against the adverse effects of junk food.
Dr. Paula Pebsworth, a primatologist at the University of Texas at San Antonio, noted that while this behavior could serve as a coping mechanism for the macaques, a more effective solution would be to reduce or eliminate the provisioning of human foods. "While geophagy may serve as a coping mechanism, a more effective management approach is to reduce or eliminate the provisioning of human foods," she stated.
As researchers continue to study the effects of human interaction on the Barbary macaques of Gibraltar, the implications of their findings could lead to better management practices to ensure the health and wellbeing of these unique primates.
Originally reported by The Guardian. View original.