Gibraltar's Monkeys Turn to Soil for Digestive Relief

On Gibraltar's busy tourist site, resident monkeys often consume junk food from visitors, leading to stomach upset. Scientists found these monkeys resort to eating soil to mitigate digestive issues. The behaviour, which might have antacid-like effects, shows potential for social learning among the macaques.

On Gibraltar's bustling tourist site, the native macaques are a familiar sight, often seen scavenging for food from visitors. This habit has led to digestive issues among the monkeys, prompting scientists to investigate an intriguing behaviour they exhibit—soil-eating.

Recent research indicates that these monkeys ingest soil, rich in clay, to counteract the adverse effects of human junk food on their stomachs. The behaviour, akin to humans consuming antacids, might help neutralize stomach acidity and enhance gut microbiome health. Instances of soil consumption were notably higher in monkeys with greater exposure to tourist snacks like chocolate and crisps.

The study, conducted by a team of researchers led by Sylvain Lemoine from the University of Cambridge, suggests that soil-eating could be a socially learned behaviour. The findings highlight how these primates adapt to their changing environment, potentially impacting tourist attitudes and informing regulations against illegal feeding.