A four-month study was conducted on three groups of free-ranging, provisioned Barbary macaques (Macaca sylvanus, L) on Gibraltar in 1992. The groups exhibited marked contrasts in the levels of provisioned, tourist-derived and natural foods in their diet, which related to differences experienced in the level and nature of human visitation.
Feeding on natural plant items accounted for only 17-20 per cent of feeding records at all sites, whereas provisioned food was the dominant element (over 75% of records) at the least visited group. In contrast 51.7 per cent of items consumed at the site most used by tourists (Apes’ Den) involved tourist-derived foods, with provisioned food contributing only 28 per cent of feeding records. The high caloric content of tourist-derived foods together with their dominance in the diet at Apes’ Den is implicated in the well-documented weight-related problems affecting this group.
Current levels of uncontrolled tourist feeding present a health and welfare threat to the Barbary macaques of Gibraltar, particularly the Apes ‘ Den group. Future management plans must recognize and seek to remedy the negative impacts of tourism.