After documenting the plants, we turned our attention to a much more difficult question: Where did this medicinal knowledge come from? I knew that in ancient India, whole books were written about how to care for elephants. But, many of the plants we learned about from the Karen were not in those books. Was the knowledge of how to use these plants coming from human medicine, which people then applied to elephants? 

After interviewing the mahouts further, we learned that many of these plants are used for people in the same way that they are used for the elephants. The plants used to treat elephant eye infections and cataracts, for example, were the same remedies used for eye infections and cataracts in people. In fact, there was a surprising overlap: Fifty‑five percent of the elephant medicines had the same use for people! It seemed clear that much of the veterinary knowledge was coming from human medicine.

Yet, despite this clear connection, there seemed to be another source of knowledge—the elephants themselves! Several of the elephant medicinal plants didn’t have any uses in human medicine. And many medicinal plants were sought out by elephants.

Mahouts reported that 84 percent of these plants were eaten by elephants when they were free to choose their own diet in the forest. So, the elephants were independently eating many of these medicines. Did they know that these plants were medicinal? Was it possible that they might be eating some of these plants because they were medicinal, the same way that we sometimes eat things because we know they are good for our health?

To prove scientifically that elephants eat medicinal plants on purpose would be challenging. It would require feeding observations, health assessments, and laboratory analysis. But, the Karen mahouts weren’t interested in having their knowledge scientifically validated. After generations of observing elephants in the jungle, many of them believed that the elephants did eat specific plants to treat specific problems. 

Karen mahouts reported 19 plant species that were used by the elephants themselves to treat constipation, indigestion, or intestinal parasites. They found plants to strengthen their teeth and to increase milk production after giving birth. Quite a few of these plants were the same ones used by the mahouts when they prepared medicine for the elephants!

Things were becoming clearer. Many of the medicines used to treat elephants had come first from human medicine. But, some plants were used by the elephants first. Only later did people observe this and start to gather them. Other medicines were used in both human medicine and elephant diets, so it was hard to tell if they originated from human knowledge, elephant knowledge, or both.

In our human-centered world, it can be hard to remember that other species have their own knowledge, which sometimes can be even greater than our own. We learned how to build dams from beavers. We saw how to survive the cold from fur- bearing animals. We copy the shapes of airplanes from birds. A whole branch of design called “biomimicry” is devoted to using the forms and processes of nature to design new human technologies.

In the forests of Southeast Asia, Karen mahouts have lived alongside Asian elephants for so long that they have borrowed from elephant knowledge. Like so many other animals, elephants seem to have a detailed knowledge of the plants they consume.

The next time you see your dog or cat chew up strange plants in the yard, watch closely, and ask yourself: “Do they know what they’re doing?” Maybe. There are many things about even our closest animal companions that we don’t yet know. There is much to be discovered!