1699 | The Philippines

Long-tailed macaque (Macaca fascicularis) clam opening

In animal behaviour, an ‘anecdote’ is an unverified or one-off report. The label is often used to contrast brief observations of unusual activities with the results of carefully planned scientific studies. And because ethology is only a relatively recent science, accounts of animal tool-use before the twentieth century often fall under the anecdotal umbrella, even if the observer was dependable and later proven correct.

Today’s tale of animal tool use is certainly brief and unverified, and it remains to be seen whether it was ever true. The report comes from a 1699 book by the former Italian lawyer Giovanni Francesco Gemelli Careri, who spent the last decade of the seventeenth century touring the world (his record of those voyages is the aptly-named Giro Del Mondo). In between visits to the Great Wall of China and the enormous Mesoamerican pyramids of Teotihuacan, Gemelli Careri spent a few months in the Philippines waiting for his next ship.

This is our guy, fresh off the boat:

Dentro una pietra

Gemelli Careri made the most of his time in southeast Asia, diligently writing down everything he saw and heard. The index to Part V of Giro Del Mondo has a succinct entry: ‘Scimmie, e loro proprietrá’ (or in English: monkeys, and their properties). Turning to the relevant section, headed Animals, Birds and Fishes of the Philippines, we find mentions of wild monkeys using both wood and stone tools, and even some using their tails as a fishing lure.

Translated into English—with the italics in the original text—Gemelli Careri writes:

There are infinite monkeys in the mountains: and of such monstrous size, that in Samboangan several of them (so they say) defended themselves with wooden branches from a Pampango soldier who wanted to insult them; so that shortly afterwards the soldier died from fear.

…

At times it seems that these monkeys surpass men in a certain degree of shrewdness; since, when they cannot find fruit on the mountain, they go down to the seashore to procure crabs, oysters, and similar things. There is a species of clam called Taclovo, which has many pounds of meat, and which usually stays open on the beach. Now the monkey, fearing that, if she comes too close, it will close on her paw when she goes to eat; she first throws a stone into the clam in order to prevent it from closing; and may then devour it at her ease, without fear of being attacked.

There is also a species which, in order to capture a crab from a hole, places its tail inside; so that, when the crab grabs it, in one stroke the monkey pulls him out.

These are the very definition of anecdotes. There is no supporting proof either from other travellers of the time, or subsequently from scientific research. However, this doesn't mean they are made up. The claims don’t fall wildly outside the realms of probability (except perhaps the poor Filipino soldier terrified to death by stick-wielding monkeys).

For example, we know that wild capuchin monkeys in Brazil regularly use stick tools, for probing into crevices in search of food. We also know that wild macaques of the same species found in the Philippines (Macaca fascicularis) use stone tools in Thailand and Myanmar to open oysters and other shellfish, as well as crabs and nuts. The photo at the top of this post is one I took of an island monkey at Khao Sam Roi Yot National Park in Thailand, eyeing up an oyster to strike with the stone tool in her left hand.

Those latter monkeys don’t have access to the giant clams (Tridacna sp.) that Gemelli Careri identifies as taclovo, because the clams live in coral sands absent from Thai and Myanmar mangrove habitats. But it is conceivable that wild macaques in the Philippines could learn to block open these huge, beautiful bivalves using stones—those in Thailand have been recorded moving and using stones weighing several kilograms. And various Asian macaque species are adept at stone handling, in which the monkeys carry, rub, cuddle, lick, roll, throw and pound collected stones without any clear outcome beyond play and mental agility. Researchers studying stone handling have suggested that it fits into the same patterns as foraging for food, just without the food part.

This short video from the Smithsonian, featuring stone handling expert Prof. Mike Huffman, introduces the activity via some Japanese macaques:

Our own ancient stone-tool-using relatives were living in the Philippines around 700,000 years ago, alongside these monkeys. The monkeys have had ample time to watch other primates using stones. Just because we don’t see a given behaviour today doesn’t mean it didn’t happen: if the seventeenth-century report is valid, it could be that macaque behaviour has been altered since by the decline of giant clams and increasing human interference in the intervening centuries. Or it may have just been a passing fad among a group of stone handling monkeys.

An aside—Tridacna nurseries like this one in the Philippines are now attempting to reverse the loss of these vulnerable creatures:

And what about those clever moneys that use their own tails to lure crabs out of holes? We know that other monkeys have learned to use their tails as an attached tool, for example by dipping it into a water hole that is too deep to otherwise reach. The idea of deliberately exposing a pain-sensing part of the body to repeated crab pinching isn’t an appealing one, but again it is not impossible.

In the case of the stone tool use, at least, there are still opportunities to test the anecdote. All we need are enough archaeological examples of giant clams killed in the seventeenth century or earlier, directly associated with stones big enough to hold open their shell. Or perhaps just a single camera phone video of a monkey performing this behaviour today. Whichever’s easiest.

Further reading

For the curious, or those hoping for a better translation, here’s the original Italian text from Giro Del Mundo, Part V, Book 1, pages 91-92:

Si truovano anche ne'monti infinite scimmie: e di tal mostruosa grandezza, che in Samboangan una fiata alcune di esse (come narrano) si difesero, con legna nelle branche, da un soldato Pampango, che volea offenderle; sicche di là a pochi di il soldato si morì, per la paura.

…

Sembra alle volte, che tai scimmie superino, in una certa tale accortezza, gli stesli uomini; poiche, non trovando frutta terrestri nel monte, vanno a procacciarsi granchi al lido del Mare, ostriche, e cose simili. V'ha una spezie d'ostriche detta Taclovo, che ha molte libbre di polpa, e suole stare aperta al lido. Or la scimmia, temendo, che, venendosi quella a serrare, quando và per mangiarla, vi rimanga chiusa la sua branca; vi gitta primamente dentro una pietra, acciò, impeditole il chiudersi; possa a suo bell'agio divorarla, senza paura d'essere ofsesa.

Ve n'ha una spezie con coda, che per torre il granchio, la pongono entro il buco; acciò, quando egli l'afferra, in un colpo ne lo tragga fuori.

Sources: Gemelli Careri, G.F. (1699) Giro del Mondo. Part V, Book I. || Haslam, M. et al. (2017) Primate archaeology evolves. Nature Ecology & Evolution 1:1431–1437. || Ingicco, T. et al. (2018) Earliest known hominin activity in the Philippines by 709 thousand years ago. Nature 557:233–237. || Pelletier, A. et al. (2017) Behavior Systems Approach to Object Play: Stone Handling Repertoire as a Measure of Propensity for Complex Foraging and Percussive Tool Use in the Genus Macaca. Animal Behavior and Cognition 4:455-473. || Castro, S. et al. (2017) Techniques Used by Bearded Capuchin Monkeys (Sapajus libidinosus) to Access Water in a Semi-Arid Environment of North-Eastern Brazil. Folia Primatologica 88:267-273.

Main image credit: Michael Haslam, Thailand 2015 || Second and third image credits: Gemelli Careri (1699) || Fourth image credit: David Greedy/Getty Images