Gibraltar monkeys eat soil in junk food detox: study

GIBRALTAR

A colony of macaques that gorge on snacks offered by tourists in the British territory of Gibraltar swallow soil to recover from their junk food binges, a study has found.

Believed to originate from North Africa, the roughly 230 primates are the main attraction in the British exclave of 30,000 people that borders southern Spain, according to the Gibraltar Ornithological and Natural History Society.

Signs dotted around Gibraltar remind visitors of a ban on feeding the macaques, with infringements punishable by fines of up to 4,000 pounds ($5,350).

But the rules are hard to enforce given the large numbers of daily visitors to “The Rock.”

The marauding monkeys brazenly snatch ice cream, cakes and crisps from unwitting tourists in addition to gobbling abandoned leftovers from bins or food directly offered to them.

These unhealthy treats have contributed to modifying a diet usually made up of fruit, vegetables and seeds.

To soothe the resulting stomach aches, the macaques have developed a habit of “geophagy, the deliberate consumption of earth,” a recent study has found.

Experts say their research reported this behavior “for the first time” among the monkeys.

“Geophagy occurred at exceptionally high rates compared to other macaque species and locations, and it was more common in summer when tourist numbers peak,” the study said.

In contrast, the behavior was not observed in a group of Gibraltar monkeys that have no contact with visitors, “a strong argument for this association between soil-eating and human food”, said Sylvain Lemoine, who co-authored the study.