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Chimps help farmers ‘plant’ cacao in Guinea

  • Researchers examined the seed-dispersing behavior of western chimpanzees (Pan troglodytes verus) in southeastern Guinea while interviewing area farmers.
  • They found that chimps feeding at cacao plantations in turn “planted” cacao seeds in agricultural fields and forests when they deposited them in their feces.
  • Farmers in the region were observed expressing annoyance at chimps feeding on their crops, but also tended cacao established by them.
  • The researchers say this behavior could be economically beneficial to farmers and discourage retaliation against chimps.

Human-wildlife conflict is an ongoing drama playing out all over the world, from southern India where plantations are forcing humans and elephants into closer proximity to the western U.S. where wolves and ranchers vie over livestock. But new research published recently in the International Journal of Primatology finds that when it comes to cacao farming in the Republic of Guinea, humans and wildlife engage in partnerships that can benefit both parties.

The study focused on Bossou, a town in the far-southeastern Nzérékoré region of Guinea and the heart of the range of the Critically Endangered western chimpanzee (Pan troglodytes verus). Once covered in lush Upper Guinean rainforest, around 1 percent of the region’s primary forest remains today, according to the UN’s Food and Agriculture Organization (FAO). As forest is converted to farmland or timber, the authors write that wildlife like chimps are increasingly exposed to crops and often consume them.

Cacao is one of the chimps’ favorite crops, according to the researchers. Native to West Africa, cacao is commonly grown in small-scale plots in Guinea.

Data from the University of Maryland and visualized on Global Forest Watch shows Guinea lost around 6 percent of its tree cover between 2001 and 2014, and the region where the study took place lost nearly 7 percent. Tree cover loss appears to have increased in recent years, jumping 600 percent between 2012 and 2013.

But while humans do the tending of their crops, they don’t always do the planting.

“Chimpanzees ingest the cacao pulp and either spit out the large seeds in unripe cacao fruit or swallow the seeds from ripe cacao fruit, which are consequently deposited in feces,” said Kimberley Hockings, Research Fellow at Oxford Brookes University and lead researcher of the study.

Often, these feces – and the cacao seeds contained within – are deposited in forest areas, where thick canopy cover blocks the light needed for cacao to reproduce. Here they grow, but do not produce fruit.

But sometimes, chimps defecate in or near agricultural fields, effectively “planting” new cacao plants and potentially adding to farmers’ yields.

Through interviews, the researchers discovered that even forest-planted cacao could benefit farmers, with established plants at-the-ready if they expanded their fields into adjacent forest. By clearing trees around them, the cacao could fruit and the farmers didn’t need to wait for the plants to grow to maturity. (In an email to Mongabay, Hockings noted that farmers don’t necessarily clear more forest because of chimp-planted cacao, but simply tend it when they choose to do so for other reasons.)

Cacao pods in Madagascar. Photo by Rhett A. Butler

The researchers say their findings show that instead of being a negative behavior, the consumption of cacao crops by wild chimps could be financially beneficial for farmers. This, they write, may help dissuade farmers from retaliating against chimps in ways that could potentially harm the animals.

“In general, farmers express annoyance when chimps (or any other wildlife) feed on their crops,” Hockings told Mongabay. “At Bossou local farmers are quite tolerant due to their traditional beliefs. At other sites farmers can engage in retaliatory killings of ‘problem’ chimpanzees.”

The study states that because of their benefit to farmers, chimps’ cacao-planting behavior could increase their own chances of survival – and with it, those of other species like the brown lemur, which depends on tree species propagated by chimps when they feed on forest fruit. And with data showing tree cover loss rates rising in Guinea as a whole and Nzérékoré in particular, this ecological service may become even more important as time wears on.

“This research has highlighted the possibility that the dispersal of crops by animals at other sites has the potential to positively impact the ability of wildlife to coexist in human-impacted habitats, especially if farmers gain economic benefits through the wildlife’s dispersal of crops,” Hockings said. “It’s also interesting from the perspective of chimpanzees creating their own niche.”