The world's leading national and international media recently reported the discovery that chimpanzees use insects to treat wounds, not only their own but also those of their companions. This extraordinary discovery was made by Italian researcher Alessandra Mascaro.

What was your path to studying chimpanzees in Africa?
I began my university career in Bologna, where I graduated in Natural Sciences. There I completed my internship at the Centro tutela e ricerca fauna esotica e selvatica in Monte Adone, Sasso Marconi. Like many people who approach the natural sciences, I was fascinated by lions. I had actually gone there to study them, but then I fell in love with chimpanzees. After that I moved to Padua, where I graduated in Evolutionary Biology. For my thesis, I contacted the University of Turin to take part in their research project in Madagascar, in the Maromizaha forest. There I focused on a bio-acoustics study of Propithecus diadema, a species of sifaka [lemurs, ed.]. Then I took the plunge and left. I found an advertisement by Tobias Deschner, a primatologist at the Max Planck Institute, for a primatology project on chimpanzees, and a month later I was already there.

What do you study at the Ozouga chimpanzee project?
In 2017, although the centre is older than that, most of the adult males in the group were habituated to the presence of observers. That is, we were able to follow and study them without frightening them. This made it possible to follow focal individuals and collect data. The Ozouga chimpanzee project studies a bit of everything — there are several research projects. For example, one very important and well-known study concerns the predation of tortoises, using a specific technique for opening them. Another behaviour, observed only here, is the use of tools to extract honey from bees that build underground nests. Other studies concern hunting. We essentially cover everything. Each chimpanzee community has its own set of behaviours, some very different, some shared, and others that are entirely new.

What is the relationship between you and the chimpanzees?
We have to be ghosts. We cannot create any kind of interaction, for several reasons: mainly because it influences behaviour and therefore affects data collection; and also because it can be very risky, since they would draw you into their group dynamics, their displays, their quarrels, and so on. They know we are there, like ghosts watching them, and that we don't smile. If they look at us, for example, we look away. The same happens when the males perform their displays — they stand up, puff themselves up and come towards you. It can be quite frightening, because fifty kilograms of chimpanzee bearing down on you can be intimidating; so you stay calm and look away — I look at my hands. As a precaution we always maintain a minimum safe distance of eight metres, even when walking together. Walking with them makes you feel a little like part of the group, even though you are not. They know you, they know who you are. For this reason, likes and dislikes sometimes develop: with some researchers they are more relaxed and at ease, while with others they are more alert and suspicious.

Your discovery went around the world. Before going into detail, what does it feel like to make a discovery of this magnitude?
I have always had an attentive and curious eye, but I never would have thought that my observation could go around the world. The day the paper came out there was a real explosion of news coverage — everyone was talking about it. I have realised my dream of being with chimpanzees, where I feel at home, and I hope to do it for the rest of my life. Managing to make a discovery like this is somewhat inexplicable, because it is truly enormous. We have shaken a huge tree on the subject of pro-social behaviour and animal empathy. So it was not just the act of treating wounds. Now I hope to be up to the task of carrying this forward. I already knew I loved it, but reaching this level is extraordinary.

It was a day like any other, amid observations and data collection, when an unexpected behaviour appeared. What happened that day in the forest?
Suzee's family is undoubtedly my favourite. When Suzee joins the group, my colleagues let me know over the radio. She is the mother I first saw performing the treatment. Suzee has a very interesting family dynamic — she is a super mum. She lets her children discover the world freely, she doesn't hold them back. She lets them explore and then goes to retrieve them. The relationship between mother and young has always fascinated me; it is another of my great passions. When I filmed the application of an insect for the first time, I knew that the day before, Sia, her adolescent son, had injured his foot. And as always, I was collecting data and filming. At first I hadn't paid much attention to the entire sequence, partly because some moments resembled others I had already seen, such as the act of tearing leaves.

What caught my curiosity was that Suzee was holding her son's foot in her hand and kept bringing it close to the wound. That evening, back at the research centre, I still had in mind the strange thing I had seen. I watched the video again — at least twenty times, I think. I immediately called Lara, my very dear friend and co-author of the paper. Then everyone else. Some said it was nothing, others were very surprised. The problem with chimpanzees is that sometimes they display a behaviour and then who knows when you will see it again. As luck would have it, however, just over a week later Lara and I saw and filmed that behaviour again. The reason no one had noticed it before is probably that the entire sequence unfolds very quickly, and all it takes is a moment's distraction to miss it — and you end up thinking that perhaps they are simply licking the wound.

At a behavioural level, which is more surprising — the medicating or the altruism?
It's difficult to say, because both aspects have a significant impact on future research, both in the medical field and in the social one. Undoubtedly, pro-sociality has attracted a great deal of attention. My first footage was of a mother treating her child, and at a fitness level that is far more explicable. The incredible moment came when Lara filmed other individuals applying the insect to the wound of Littlegrey, an adult male. In the video you can actually hear Lara say "incroyable, incroyable". You could see Carol, an adult female, bringing the insect and placing it on the wound; Thea and Ngonde, adult males, touching it with their finger; and Littlegrey letting it all happen. These individuals are not related on the maternal line, and this discovery was the real breakthrough of the research. Seeing an animal other than a human treat its own wounds and those of others is something extraordinary, entirely new. Placing it between the lips, pressing it — because it isn't chewing — and putting it on the wound. They used a resource for potentially medical purposes, and that is science. One could speak of chimpanzee doctors, because they managed to understand the problem of one of their companions and adopt a behaviour apparently aimed at resolving it, all together.

Have you managed to identify which insect, or which insects, are being used?
Taxonomically we don't know yet, but we're working on it. Identifying the species is very difficult for several reasons; first of all, the handling: during use they put it in their mouth, press it between their lips, place it on the wound, pick it up again, put it back in their mouth. They repeat this sequence several times and almost nothing is left of the insect. Then, once they've finished, they discard it on the forest floor, and it's like looking for a needle in a haystack. In recent months we have maximised the protocol — we follow them from the first to the last day until the wound heals completely. In this way we accompany them throughout the entire healing process. We are also using high-resolution cameras in order to maximise the chances of filming the insect during use. Whatever happens, it is very difficult, but I am confident we will manage it.

What does it mean to be a researcher today, and how important is this work for protecting biodiversity and safeguarding species?
You have to bet on yourself. At first you start out as a volunteer to build up your CV and gain enough experience to move up. You need a great deal of passion. I work in the forest, a very complex environment that demands a great deal of attention. For example, every day we work surrounded by forest elephants and you can never truly relax. You are focused on your chimpanzee while at the same time having to pay attention to everything around you, because an elephant could charge you at any moment. It is risky, and if you're not physically fit, or don't have a strong level of motivation, you break down. I have seen people quit out of fear.

Researchers today need additional incentives, first and foremost financial ones, because if you don't have a family to fall back on or any savings strategy, it is very hard. Protecting nature doesn't mean only safeguarding the keystone species that everyone knows — you have to protect the entire habitat, so that all the dynamics of the ecosystem function properly. Unfortunately, we live in a society where there are children who have never seen a chicken: it is hard for them to understand any of this. The whole world needs protecting, not just the chimpanzee.