Contrasts in Diet Amongst Barbary Macaques On Gibraltar: Human Influences
Abstract: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.