Dispersal of a Human-Cultivated Crop by Wild Chimpanzees (Pan troglodytes verus) in a Forest–Farm Matrix
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With the conversion of natural habitats to farmland, nonhuman primates (hereafter primates) are increasingly exposed to agricultural crops. Although frugivorous primates are important seed dispersers that sometimes feed on agricultural fruits, evidence for dispersal of crops by primates is lacking. Here, we examine flexible feeding on cacao (Theobroma cacao) fruit and seed dispersal patterns by chimpanzees (Pan troglodytes verus) at Bossou in Guinea, and consequent cacao germination and survival. From direct observations, we confirm that cacao fruit is not an important food to chimpanzees, representing 0.23 % of focal animal feeding time. Chimpanzees ingest cacao pulp and either spit out the large seeds intact from unripe cacao fruit or swallow the seeds from ripe cacao fruits, which are consequently deposited in feces. From ecological surveys we show that chimpanzees distributed cacao extensively throughout their home range, at a mean distance of 407 m ± SE 0.6 (N = 90 clusters, range: 4–1130 m) from cacao plantations. As distance from the cacao plantation increased, cacao plants were more likely to survive. Other factors, including number of cacao plants in a cluster, plant height, and openness of the understory did not predict short-term cacao survival. Cacao plants within the forest did not produce fruit. By contrast, when chimpanzees deposited seeds in a plantation, cacao plants produced fruits as a result of farmers’ maintenance of the area. Our local-scale findings emphasize the complex behavioral and ecological interconnections between coexisting humans and primates in agricultural landscapes and generate interesting questions regarding primate niche construction and crop “ownership” related to who “plants” the crop.
KeywordsAnthropogenic habitat Cacao (Theobroma cacao) Cultivated foods Human–wildlife interactions Niche construction Seed dispersal
We thank the DNRSIT and A. G. Soumah, director of the IREB, Guinea and local research assistants, especially B. Zogbila, for invaluable help and Bossou villagers for continuing support. We thank J. R. Anderson for initial discussions, A. Friend for GIS advice, and G. Donati for comments and statistical advice. The manuscript was greatly improved by comments from M. McLennan, N. Spagnoletti, J. Setchell, and two anonymous reviewers. Research was supported by an early career fellowship IF/01128/2014 and research grant PTDC/CS-ANT/121124/2010 to K. Hockings from Fundação para a Ciência e a Tecnologia, Portugal, and MEXT grant 24000001, JSPS core-to-core CCSN, JSPS leading graduate program U04 to T. Matsuzawa.
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Conflict of Interest
The authors declare that they have no conflict of interest.
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