Status of urban populations of the long-tailed macaque (Macaca fascicularis) in West Sumatra, Indonesia

Abstract

We studied long-tailed macaque (Macaca fascicularis) populations in Padang, West Sumatra, Indonesia, focusing on the effect of human provisioning on their demography and dietary composition. We conducted a field survey at three sites in the city: Gunung Meru, Gunung Padang, and Gunung Panggilun. Mean troop size (range 28-68) and infant ratio (range 0.38-1.00) were greater in Gunung Meru, where the macaques have been highly provisioned, than at the other two study sites (troop size 10-15; infant ratio 0.00-0.33). The macaques at all sites consumed both natural and human foods, but dependence on the latter differed among sites: three-quarters of the diet of macaques in Gunung Meru consisted of human foods, while human foods comprised less than 5% of the macaque diet at the other sites. The ability of macaques to modify the proportion of human food is a behavioral flexibility that facilitates the survival of the long-tailed macaque in urban habitats. Without restrictions on provisioning, the degree of dependence of macaques on human foods and population size could increase, especially in Gunung Meru, and human-macaque conflict could escalate. In order to create an effective management policy for urbanized monkeys, long-term quantitative data on macaque behavior and monitoring of population parameters are required.

Effect of Provisioning on the Temporal Variation in the Activity Budget of Urban Long-Tailed Macaques (Macaca fascicularis) in West Sumatra, Indonesia

“…The most likely reason for these differences is the varying degrees of provisioning that exist at the two sites. As the popular monkey tourist site in Padang, tourists and local people fed the macaque at GM daily for pleasure and religious purposes [Koyama, 1984;Ilham et al, 2017]. As a result, provisioning foods are available throughout the year, resulting in macaques waiting rather than searching for their own resources, which indirectly elongated the time spent in resting.…”

“…The dominant plants were common at both sites: Ficus elastica, F. benjamina (Moraceae), Alstonia scholaris (Apocynaceae), Arenga obtusifolia (Arecaceae), Eurya acuminata (Theaceae), Cocos nucifera (Arecaceae), and Mangifera indica (Anacardiaceae), but a detailed vegetation survey of these sites has not been conducted. The macaques at GM totaled 132 animals in 3 groups (A, B, and C) and were intensively fed by tourists and local people, and they consumed large quantities of human foods (70% of feeding time spent on provisioned food), while macaques at GP (15 animals in 1 group, named X) depend less on human foods (<5% of feeding time spent on provisioned food) [Ilham et al, 2017]. At GM, tourists tended to feed the macaques mostly at the provisioning ground (western part of the GM) which is inside the home range of the C group.…”

“…Tourists dropped food on the pavements or threw food out of their car windows or handed it out. The provisioned food mainly consisted of boiled peanuts, roasted peanuts, bread, snacks, and vegetables [Ilham et al, 2017].…”

“…The inclusion of human food in the diet can have significant effects on activity budgets [Brennan et al, 1985;Fa, 1986;Altmann and Muruthi, 1988;O'Leary and Fa, 1993;Saj et al, 1999;Sha and Hanya, 2013a]. Several studies have shown that the amount of provisioned food availability is proportional to the number of tourists [Ram et al, 2003;Ilham et al, 2017].…”

“…Food provisioning has become a popular tour- 349 Folia Primatol 2018;89:347-356 DOI: 10.1159/000491790 ist attraction in Padang [Ilham et al, 2017]; however, it is causing the macaques to invade human settlements and seek out human foods [Ilham, pers. observation].…”