We consider using tools as being a tremendous sign of intelligence. Animals that can use tools are smarter than those who cannot. And those who can make tools are even smarter than those who use the ones laying around. But also, how are those tools being used? Scientists found that macaques use their stone tools differently, despite living in the same environment.
Macaques are actually the only species of monkeys in the Old World that knows how to use tools. They use them to open shellfish, including oysters, crabs and mussels or crack nuts in rarer occasions. In other words, stone tools for macaques are needed solely for food preparation. Macaques live in Asia, North Africa, and (in one instance) Gibraltar. And, as this new study showed, they use virtually the same stones to make tools and use them for the same purpose, but use them differently.
This is quite an interesting discovery, because scientists have previously believed that our behaviour is influenced by the environment much more. In other words, we find a stone and use it in the most convenient way. However, macaques’ stone tool use varies despite same environment. Scientists collected 115 stone tools combined from Boi Yai Island and Lobi Bay island in southern Thailand, within the Ao Phang Nga National Park. They assessed the wear pattern on these stones and found significant differences.
For example, the stone tools on Boi Yai Island showed a greater number of wear patterns. They are also generally bigger than the ones used in Lobi Bay. One one hand, oysters on Boi Yai Island are bigger, but scientists believe that these differences are not due to environmental factors – they are examples of learnt behaviour.
Dr Lydia Luncz, lead author of the study, said: “That we find a potential cultural behaviour in macaques is not surprising to us. The interesting part is that the same foraging behaviour creates distinct tool evidence in the environment. This might be useful to keep in mind when we look at the archaeological record of human ancestors as well”.
So it seems like some of the techniques of using tools evolved independently in different populations. This is very interesting and could provide us with a deeper insight into human evolution as well. However, scientists are worried about macaques in Thailand and their ability to research them.
The problem is that Thailand is increasingly popular tourist destination. Tourism is booming and many of these people want to see the macaques in action. This is likely to impact their behaviour, especially if irresponsible tourists are going to try to feed them in order to get better pictures. This might call for better conservation methods in the future.