Science2 publishers3 min readPublished Updated
Camera traps at 14 Senegalese sites film chimpanzees handing their tools to youngsters
Fifteen hours of footage from Dindefelo yielded 33 handovers of dipping sticks and other tools, most of them between relatives, with adults giving up ants they could have eaten to infants who then fished for themselves.
The Scientist · Science desk
What happened
- Researchers from the University of Barcelona and the Jane Goodall Institute Spain analysed almost 15 hours of camera-trap footage shot between 2017 and 2025 at the savanna site of Dindefelo, Senegal.
- The cameras, placed at 14 spots where wild western chimpanzees were already known to use tools, caught 33 tool transfers between individuals plus four handovers of fruit.
- Adults, especially females, were 58% of the original holders of the transferred objects, and infants were the largest group of recipients at 42%.
- Most objects passed between relatives, and 30% of all transfers went from a mother to her own offspring.
- A separate 30 minutes of footage from 11 baobab-pounding sites caught a juvenile male cracking a fruit against rock in front of the infant Fotti and then guiding his hand to one.
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Why it matters
- constraint The study can point to how transfers might help a youngster learn, but not how much of its learning speed they account for: no count of filmed tool-use bouts was reported, and no individual infants were followed up.
- contradiction Whether the same dataset shows tolerated begging or instruction depends on which part is weighted: youngsters solicited nearly every voluntary transfer, while the two published videos show the adult moving first.
- capability Because the donor's lost meal is visible on film, camera traps at known tool sites can now score the animal-behaviour test for teaching instead of inferring it from field notes.
- precedent Two of the four behaviours filmed are restricted to one regional population, so extending the teaching claim to chimpanzees generally requires the same footage from eastern and central sites.
Whether any of this counts as teaching turns on a definition field researchers keep deliberately strict. Andrew Whiten at the University of St Andrews told New Scientist that the Dindefelo observation "fits the criteria for teaching used in animal behaviour research - that the behaviour benefits the pupil's opportunities to learn, and is done despite having a cost to the teacher." [23] The cost the team logged was food. During the filmed interactions, the donor forgoing the ants or the fruit was the teacher. [22]
Andreu Sánchez-Megías, the study's first author, said: "Tool transfers thus appear to be a form of teaching, together with observation and supervised practice. It appears that mothers are the main models and teachers for young chimpanzees in this manner." [20] The aggregate numbers put a condition on the first half of that. All but one of the voluntary transfers appeared to happen at the recipient's initiative [11]. Some objects were taken outright, and the dispossessed chimpanzee sometimes hit the thief or grabbed the object back [12]. An adult tolerating a persistent infant is a weaker claim than an adult instructing one. In both published videos the older animal moved first. Soukki loaded the stick before pulling Saïsaï over to it [13], and the juvenile male pounded a baobab fruit in front of Fotti before guiding his hand to one [14].
Fifteen hours is the base for any rate here, and those hours were selected. The cameras sat at 14 places where these chimpanzees had already been recorded using tools [3]. That placement is why eight years of trapping produced 33 transfers at all. Over roughly 15 hours, 33 comes to about two per hour of footage [2]. Neither account reports how many tool-use bouts the cameras caught in total, or how infants who received tools fared later against those who did not.
The two published accounts report the same 33 transfers differently. New Scientist gave counts, 19 transfers during ant dipping, 10 during algae fishing and four during termite fishing [8]; phys.org gave the paper's percentages of 58, 30 and 12 [7]. Nineteen of 33 is 57.6%, and the three counts sum to the reported total [1][3].
Where the behaviours occur limits how far the result travels. Ant dipping and termite fishing turn up in communities of all four chimpanzee subspecies, while algae fishing and baobab pounding are known only from western chimpanzees in Senegal, Mali and Guinea [17]. Algae fishing accounted for 30% of the transfers [7]. New Scientist also notes that baobab pounding is treated as proto-tool use, because the stone is an anvil the animal never holds [16].
R. Adriana Hernandez-Aguilar at the University of Barcelona said of the footage, "To actually catch it on film is important and was very surprising for us." [21] Elliot Howard-Spink at the Max Planck Institute of Animal Behavior, who was not part of the team, said: "Teaching events are quite rare and difficult to study because only so many learning attempts are needed until an individual learns a behaviour." [24] He also said: "Showing across many forms of tool use that these tool transfers are indicative of a very simple form of teaching is very cool and nice." [25]
What to watch
- Whether follow-up work tracks named individuals such as Saisai and Fotti over time, so acquisition speed with and without transfers can be compared.
- Whether camera traps at eastern or central chimpanzee sites record the same transfers, since algae fishing and baobab pounding are only known from Senegal, Mali and Guinea.
- Whether other teams score the cost-to-teacher criterion on film, the test Whiten singled out.