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Selection and transport of materials for tools is ubiquitous throughout our species' evolutionary history. Yet our understanding of early human material culture is heavily skewed toward lithic technology. This poses challenges when reconstructing our technical origins, as organic raw materials, especially plants, likely played a significant role despite their absence from the record until 300 kya. Studies of plant-tool use by living apes can serve as a proxy to reconstruct such aspects of human behavior. Employing archaeological methods, we investigated raw material procurement for termite-fishing tools by three chimpanzee (Pan troglodytes schweinfurthii) populations in Tanzania: Gombe, Issa, and Mahale. All communities exploited plant sources from the immediate vicinity of termite mounds, as well as farther away, and reused them. However, at Issa, more parts were sourced per plant, with the number of removals decreasing as distance from the mound increased. These disparities are likely caused by environmental differences. Issa apes might try to minimize transport costs in what is a comparably more open and drier habitat with fewer suitable sources available near mounds. Despite similar raw material types being available, Issa and Mahale chimpanzees exclusively used bark for tool manufacture, while at Gombe, various materials were employed; these differences may reflect cultural variants. Our study highlights how environmental and cultural factors shape chimpanzee technology and identifies similarities to raw material selection processes inferred for Oldowan tool users. The archaeology of the perishable, even if at its infancy, is providing a new framework for reconstructing archaeologically invisible aspects of early human behavior and our own technological origins. [ABSTRACT FROM AUTHOR]

Objectives: Acquiring tool‐assisted foraging skills can potentially improve dietary quality and increase fitness for wild chimpanzees (Pan troglodytes). In contrast to chimpanzees in East and West Africa, chimpanzees in the Congo Basin use tool sets and brush‐tipped fishing probes to gather termites. We investigated the ontogeny of these tool skills in chimpanzees of the Goualougo Triangle, Republic of Congo, and compared it to that for chimpanzees at Gombe, Tanzania. We assessed whether chimpanzees acquired simple tool behaviors and single tool use before more complex actions and sequential use of multiple tool types. Materials and Methods: Using a longitudinal approach, we scored remote video footage to document the acquisition of termite‐gathering critical elements for 25 immature chimpanzees at Goualougo. Results: All chimpanzees termite fished by 2.9 years but did not manufacture brush‐tipped probes until an average of 4.3 years. Acquisition of sequential tool use extended into juvenility and adolescence. While we did not detect significant sex differences, most critical elements except tool manufacture were acquired slightly earlier by females. Discussion: These findings contrast with Gombe, where chimpanzees learn to both use and make fishing probes between ages 1.5–3.5 and acquire the complete task by age 5.5. Differences between sites could reflect tool material selectivity and design complexity, the challenge of sequential tool behaviors, and strength requirements of puncturing subterranean termite nests at Goualougo. These results illustrate how task complexity may influence the timing and sequence of skill acquisition, improving models of the ontogeny of tool behavior among early hominins who likely used complex, perishable technologies. [ABSTRACT FROM AUTHOR]

Although the phenomenon of termite fishing by chimpanzees (Pan troglodytes) has historical and theoretical importance for primatology, we still have a limited understanding of how chimpanzees accomplish this activity, and in particular, about details of skilled actions and the nature of individual variation in fishing techniques. We examined movements, hand positions, grips, and other details from remote video footage of seven adult and subadult female chimpanzees using plant probes to extract Macrotermes muelleri termites from epigeal nests. Six chimpanzees used exclusively one hand (left or right) to grip the probe during termite fishing. All chimpanzees used the same repertoire of actions to insert, adjust, and withdraw the probe but differed in the frequency of use of particular actions. Chimpanzees have been described as eating termites in two ways—directly from the probe or by sweeping them from the probe with one hand. We describe a third technique: sliding the probe between the digits of one stationary hand as the probe is extracted from the nest. The sliding technique requires complementary bimanual coordination (extracting with one hand and grasping lightly with the other, at the same time). We highlight the importance of actions with two hands—one gripping, one assisting—in termite fishing and discuss how probing techniques are correlated with performance. Additional research on digital function and on environmental, organismic, and task constraints will further reveal manual dexterity in termite fishing. Research Highlights: ‐Using remote video footage from camera traps in Goualougo Triangle, Republic of Congo, we describe chimpanzees' manual actions, postures, and positions, and movements of the probe while they fished for termites in epigeal termite nests.‐Chimpanzees used diverse grips, with and without the thumb, and two hands—one gripping, one assisting—to handle the probe delicately and to move it precisely.‐We describe a new technique for recovering termites: sliding the probe between the digits of one stationary hand as the probe is extracted from the nest with the other hand, and a new action: oscillatory movements of the probe while it was inserted in the nest. [ABSTRACT FROM AUTHOR]