Story perspectives

Gibraltar macaques eat soil to offset tourist junk food

4/23/2026

Summary

Story summary

Barbary macaques in Gibraltar began eating specific soils to self-medicate against tourist-supplied junk food.
Researchers linked the soil-eating to high-sugar, high-fat snacks from visitors.
Monkeys averaged twelve soil-eating events per week, with forty-six incidents recorded between August 2022 and April 2024.
Soil consumption increased forty percent during summer months, when tourist numbers peak.
Monkeys showed distinct preferences for red clay and for tar-clogged soil from potholes.

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Story summary

Barbary macaques in Gibraltar began eating specific soils to self-medicate against tourist-supplied junk food.
Researchers linked the soil-eating to high-sugar, high-fat snacks from visitors.
Monkeys averaged twelve soil-eating events per week, with forty-six incidents recorded between August 2022 and April 2024.
Soil consumption increased forty percent during summer months, when tourist numbers peak.
Monkeys showed distinct preferences for red clay and for tar-clogged soil from potholes.