Ecology of culture: do environmental factors influence foraging tool use in wild chimpanzees, Pan troglodytes verus?

Ecological and social correlates of chimpanzee tool use

“…However, social insects do not fit the typical profile of fallback food resources [8]. While army ants may provide additional protein and micronutrients when they are consumed by chimpanzees, Koops et al [32] speculated that their nutritional contribution to the diet may not be adequate to compensate for ripe fruits during times of scarcity. It was reported that the nutritional value of arboreal ants harvested with tools at Mahale appears to be negligible [40].…”

“…By contrast, termite nests are rare and peripheral to the chimpanzee range at Seringbara in Guinea, and no evidence of tool use in this context has been detected within this population [32]. However, tool use to gather army ants has been documented in Seringbara, which may be a response to ecological opportunities as army ants are both abundant and widespread across the area [32]. The frequency of opportunities may also be key, as the mere presence of particular ant prey does not provide a sufficient explanation for the observed patterns of chimpanzee tool use [55,56].…”

“…In central Africa, chimpanzees have developed specialized tool sets to harvest termites year-round [52 -54], and ecological opportunities to harvest termites seem to be particularly abundant at Fongoli where these insects are a staple food in the chimpanzee diet [35]. By contrast, termite nests are rare and peripheral to the chimpanzee range at Seringbara in Guinea, and no evidence of tool use in this context has been detected within this population [32]. However, tool use to gather army ants has been documented in Seringbara, which may be a response to ecological opportunities as army ants are both abundant and widespread across the area [32].…”

“…Sources (page numbers refer to original publications): b Yamakoshi [31]. c Koops et al [32]. d Gunther & Boesch [33] and N'Guessan et al [34] (necessity: negative energy balance among some community members across seasons; opportunity: nut cracking tool use coincides with abundance of nuts; profitability: energetic gain from nut cracking).…”

The ecology of primate material culture

“…A number of recent studies [13][14][15] have explicitly addressed the role of ecological conditions in shaping primate foraging tool use by testing two main, not mutually exclusive, hypotheses [16]. The opportunity hypothesis states that encounter rates with tool materials and resources whose exploitation requires tools affect the likelihood of tool invention and frequency of tool use, thus explaining tool-use patterns.…”