For the first time, zoologists have captured images of endangered capuchins of the Sapajus flavius ​​species using stones as tools to search for food in the dry forests of Brazil. This puts them on par with crab-eating macaques and western chimpanzees, which use stones as tools.

When an animal wants to get tasty leaves, berries, or other treats but they are too high up, it uses a stick or other tool to reach the treats. Not all animals do this, and the list of tasks for which tools can be useful is much broader. For example, elephants drive away annoying flies with sticks, and wild Sumatran orangutans know how to place a pad of leaves in their palms to eat the leaves of a thorny tree without damaging their paws.

In this case, the tool is an extension of the animal’s body. Sometimes they too turn to stone.

For example, sea otters swimming on their backs put a stone on their chest and break a mussel shell or crab shell on it to extract meat. Five different taxa had previously been found among stone-using monkeys: two species of capuchin—black-banded (Sapajus libidinosus) And Cebus imitatorAs well as western chimpanzees (Pan primitive people verus) and two subspecies of crab-eating macaques.

The other day, Brazilian zoologists documented for the first time several cases of how rare a capuchin species is. Sapagus flavius It uses stones as tools to crack nuts and obtain food. Scientists set up four camera traps in the Catinga forests of Brazil, the largest dry forest in South America, and one of the four stations had a corn feeder. Observations were conducted from September 2022 to March 2023, and it was possible to photograph capuchins using stones near the San Francisco River. The video footage and report were published in the journal Primates.

capuchin types Sapagus flaviusAccording to 2020 data from the International Union for Conservation of Nature, it is on the verge of extinction – only 500 individuals were counted at the time. These monkeys live only in the eastern part of Brazil, on the coast of the Atlantic Ocean. It’s interesting how this was recorded anyway. S. flavius Use sticks to hunt termites.

This time, the capuchins were caught for the first time splitting food with stones. The monkeys put nuts or other hard fruits on an anvil stone and hit them with hammer stones. In total, scientists recorded eight cases of the use of such a tool. In one place, when people were building houses nearby, the capuchins used pieces of concrete as anvils. As the researchers noted, the studied capuchins became the sixth primate to use stones as tools.

It is also noteworthy that the habitat itself forces monkeys to resort to such means. The thing is that in the Brazilian Atlantic forest you can eat ripe fruit almost all year round – the diet of the already mentioned black-striped capuchins is very wide: they feed on 35 different types of fruits, climbing higher and higher in the trees.

But the Kaatinga forests are dry and hot, and only nine different kinds of fruit can be found in the dump. They also do not have enough food for eight or nine months of the year. Therefore, the Capuchins S.flavius It is necessary to feed on dry fruits such as hazelnuts, which are more common in such a lush area. In order to obtain food, you have to resort to stone tools.