In “Bonobo genius makes stone tools like early humans did” (New Scientist, 21 August 2012), Hannah Krakauer reports,
Kanzi the bonobo continues to impress. Not content with learning sign language or making up “words” for things like banana or juice, he now seems capable of making stone tools on a par with the efforts of early humans.
He did vastly better than a companion bonobo, which raises an interesting question:
Do Kanzi’s skills translate to all bonobos? It’s hard to say. The abilities of animals like Alex the parrot, who could purportedly count to six, and Betty the crow, who crafted a hook out of wire, sometimes prompt claims about the intelligence of an entire species. But since these animals are raised in unusual environments where they frequently interact with humans, their cases may be too singular to extrapolate their talents to their brethren.
Being fed, protected, and taught by humans is definitely an unusual environment.
Both apes had been taught by humans how to make the tools, though only Kanji appears to have profited from the lesson.
In a similar way, rooks can make and use tools, if taught by humans. The problem is, it is difficult to extrapolate what animals can do if humans teach them to what they will do without humans around. The fact that only a few animals perform well on these tests, even with plenty of human coaching and lots of rewards, is a clue.
Most animals likely prefer to solve their problems in a way that feels natural to them. One reason that the bonobo genius doesn’t launch a tool using revolution among his fellows is that their methods, while clumsy by comparison, more or less work, and don’t require much cognitive effort.
See also: Another claim for ape language that doesn’t pan out (also about Kanji)