Human-Monkey Conflicts in Sri Lanka: A Comment on Dittus et al., 2019

Dittus et al. [Folia Primatologica 2019;90: 89-108] discuss conflicts in Sri Lanka between people and 4 subspecies of purple-faced langurs, 3 subspecies of toque macaques and a single grey langur subspecies. All of these subspecies are endemic and also listed by the IUCN as endangered or threatened with extinction due to extensive deforestation. Nevertheless, in order to mitigate conflicts with macaques, the above article recommended buffer zones that "should be at least 100-200 m wide, devoid of trees, shrubs and food sources: pasture could serve this purpose" [Dittus et al., 2019, p. 100]. This recommendation is presented without an explicit statement that buffer zones should not be carved out of existing primate habitats. Therefore, it could be misused by corrupt politicians and timber contractors to justify deforestation, even by expanding existing pastures that do not meet the width specifications prescribed by the article. These actions could undermine the survival of both langurs that rely exclusively on a vegetarian diet. Therefore, in my opinion, buffer zones as proposed by Dittus et al. [2019] are not a valid recommendation to mitigate human-monkey conflicts (HMCs) in Sri Lanka. I consider several other statements in the article also to have questionable relevance to mitigating HMCs in Sri Lanka. However, I discuss a commercially viable activity reported by Dittus et al. [2019] that could be used to mitigate HMCs and also promote monkey conservation in Sri Lanka. It derives from a time-tested and, therefore, successful business enterprise based on peaceful coexistence with monkeys that the authors of that article have undertaken at their field site in Polonnaruwa. However, they do not discuss the enterprise's proven ability to promote peaceful coexistence with monkeys.Therefore, I explain how the enterprise could help communities throughout Sri Lanka to accrue financial benefits, by practicing peaceful coexistence with all monkey subspecies and promoting their conservation at the same time. This business model has the potential to strengthen Sri Lanka's efforts to protect its unique contribution to global biological diversity from extinction.