Interactions between human and long-tailed macaque (Macaca fascicularis) in the context of crop feeding in Mauritius

Abstract

Human-wildlife coexistence in agro–forestry systems often presents significant challenges. In Mauritius, the long-tailed macaque (Macaca fascicularis) – an introduced species – is reported as a serious crop pest by local farmers, but its crop feeding behavior remains poorly studied. Yet, understanding this behavior is essential for developing effective and sustainable mitigation strategies. We used a combination of camera trap data, crop damage assessments, and phenological survey to quantify macaque activity in agricultural fields. Specifically, we first investigated which spatial, temporal, and demographic factors influenced the duration and frequency of Crop Feeding Events (CFEs). Secondly, econdly, we sought to identify which key parameters of feeding events - among frequency, duration and number of individuals - could best predict the amount of damage caused to crops. Lastly, a questionnaire survey was conducted to examine farmers' perceptions and attitudes toward macaques. Across six study sites, we recorded a total of 776 macaque videos, including 193 CFEs. Our results showed that crop feeding group sizes were generally small, with an average CFE duration of 14 minutes. Distinct macaque activity patterns were observed between sugarcane and vegetable crops, likely influenced by human presence. We found that demographic composition the group was a key factor, with CFEs duration increasing with the size of the group and the proportion of adults. Spatial factors, such as the proportions of surrounding forest and farmland, were associated with shorter feeding events. Our research identified the frequency of CFEs as the primary parameter for determining crop loss, although the number of individuals and the duration of CFEs were also important secondary factors. Our questionnaire revealed that, overall, farmers' perceptions of macaques were predominantly negative and influenced by socio-cultural variables. People of Hindu religion, those who were younger or had a higher level of education expressed greater tolerance towards macaques. The majority of respondents (81%) also reported a marked increase in macaque visits to their cultures over the past ten years. This exploratory study offers valuable insights into the patterns and drivers of crop feeding by Mauritian macaques, which could inform future mitigation strategies. We recommend prioritizing deterrence methods aimed at reducing the frequency of CFEs. For example, the use of 'buffer' crops or enhancing the perception of risk in fields by employing guards or dogs, when feasible—techniques that remain underutilized for macaques in Mauritius. We also suggest that key CFE parameters could serve as useful measures for testing the effectiveness of future macaque deterrents. Additionally, our results underscore the importance of considering the human dimension, as poorly designed interventions may unintentionally exacerbate tensions among religious or social groups. These socio-cultural factors must be taken into account to ensure that mitigation efforts are not only effective but also socially sustainable.