Nutritional content explains the attractiveness of cacao to crop raiding Tonkean macaques

Abstract

Nutritional ecology has been linked to crop raiding behavior in a number of wildlife taxa. Here our goal is to explore the role nutrition plays in cacao crop raiding by Tonkean macaques Macaca tonkeana in Sulawesi, Indonesia. From June – Sept. 2008 we collected fruit samples from 13 species known to be important Tonkean macaque foods and compared their nutritional value to that of cacao Theobroma cacao, an important cash crop in Sulawesi. Cacao pulp was significantly lower in protein, but lower in dietary fiber, and higher in digestible carbohydrates and energy content compared to forest fruits. These findings, combined with the fact that cacao fruits are spatially concentrated and available throughout the year, likely explain why Tonkean macaques are attracted to this cultivated resource. We use these data along with published feeding ecology data to propose strategies to minimize human-macaque conflict. Namely, we recommend the deliberate protection of Elmerillila tsiampaccca, Ficus spp. and Arenga pinnata, fruit species known to be regularly consumed and of considerable nutritional value. We also identify the A. pinnata palm as a potential buffer resource to curb cacao crop raiding by macaques. Cacao is a hard-to-process food because the pods have a thick outer skin that encases the seeds and pulp. Aren palm fruit, although lower in digestibility, is easier-to-process, higher in protein, and also available year round. In addition, because the palm has considerable cultural and economic significance for local people, the strategy of planting Aren palm in a buffer corridor is likely to garner local community support.

Going to extremes for sodium acquisition: use of community land and high‐altitude areas by mountain gorillas Gorilla beringei in Rwanda

“…, Riley et al . , McLennan & Ganzhorn ) and also non‐primates ( e.g ., elephants; Osborn ). In contrast, some primates show increased reliance on agricultural crops during times of forest fruit shortages ( e.g ., Naughton‐Treves et al .…”

“…Nutritional attractiveness of cultivated plants has been shown to be a major impetus for crop-foraging behavior in some species of primates (Forthman Quick & Demment 1988, Campbell-Smith et al 2011, Riley et al 2013, McLennan & Ganzhorn 2016 and also non-primates (e.g., elephants; Osborn 2004). In contrast, some primates show increased reliance on agricultural crops during times of forest fruit shortages (e.g., Naughton-Treves et al 1998, Chancellor et al 2012, McLennan 2013.…”

Interactions with humans impose time constraints on urban-dwelling rhesus macaques (Macaca mulatta)

“…In contrast, other studies reveal that animals that live and thrive in an anthropogenic environment tend to spend more time resting and socializing than groups living in less anthropogenic areas (e.g., vervet monkey, Chlorocebus pygerythrus: Saj et al, 1999;Thatcher et al, 2019;Barbary macaque: El Alami et al, 2012;rhesus macaque: Jaman & Huffman, 2013; assamese macaque, Macaca assamensis: Koirala et al, 2017;long-tailed macaque: Ilham et al, 2018). Such beneficial effects may be due to reliance on anthropogenic foods that tends to be higher in calories, more abundant, and more digestible than natural foods (Forthman-Quick, 1988;Rode et al, 2006;Riley et al, 2013;McLennan & Ganzhorn, 2017), and researchers argue that in this condition animals can spend less time feeding, and consequently increase their time spent resting and/or socializing (Jaman & Huffman, 2013).…”

Nutritional physiology and ecology of wildlife in a changing world

“…Some crops are nutritionally attractive to wild animals and provide both energy (Sukumar, 1990; Riley et al , 2013; McLennan and Ganzhorn, 2017) and minerals (Rode et al , 2006a). However, the effects on the health of these species are poorly studied.…”