Tourists' Junk Food Drives Monkey Geophagy

Researchers observed Gibraltar’s Barbary macaques eating fistfuls of soil (geophagy) for the first time and traced the behavior to groups that consume lots of tourist-supplied junk food (chocolate, chips, ice cream). The soil‑eating appears socially learned, varies by troop and soil type, and declined in troops away from tourist hotspots; local authorities have responded with feeding bans and healthier provisioning. — Casual tourist behaviors can disrupt animal diets and microbiomes, produce socially transmitted self‑medication in wildlife, and therefore require targeted management and public‑education interventions.