Working with Orangutans, Gorillas and Black Crested Macaques


I had an amazing opportunity to work with the orangutans, gorillas and black crested macaques at the Denver Zoo through their animal enrichment program. I worked with individual zookeepers and the primates they were in charge of and designed an essential oil program for each primate.


It was truly remarkable to work with the orangutans, gorillas and black crested macaques and to see them choose what essential oil they wanted and how they wanted it; we were watching them self-medicate. Another term for “self-medicate” is zoopharmacognosy. A term coined by Dr. Eloy Rodriguez, a biochemist and professor at Cornell University, zoopharmacognosy refers to the process by which animals self-medicate. In this process, animals select and use plants, soils and insects to treat and prevent disease. The word zoopharmacognosy is derived from the roots zoo (“animal”), pharma (“drug”) and gnosy (“knowing”).

The essential oils were offered to the primates twice a day. We placed the essential oils on clean rags, bedding or food and then handed it to them and they either accepted the oil or rejected it by giving the item back to us or tossing it aside. In the case of the orangutans, the zookeeper would offer the essential oil directly, and I constantly reminded her to hold onto the bottle, because when they liked the oil they would try to take it. Sometimes they would hold out their finger and have some oil placed onto it and then they would apply it to themselves. This process truly was fascinating to watch and be a part of. For example, each orangutan had its own preference: Sally preferred hers on her lips, Robin liked his on top of his head or on food, Mias placed it below his nose or on his forehead and Allie liked the oils on her lips, fingers or toys. The oils they did not choose that day were not used.


Some of the conditions we addressed in the animals were distrust, pain, sinus problems, digestive upsets, anger, being easily aroused and fear. Some of the essential oils that we worked with were violet leaf, rose, jasmine, fennel, basil, sweet marjoram, neroli and ginger. Working with these oils and others did result in some significant behavioral changes. For instance, in regards to the orangutans: During the winter months Robin and Mias typically become more aggressive towards each other. In the past they would often spar with each other using sticks through their mesh wire fence and douse each other with water. But after working with the essential oils (they both preferred basil) the zookeepers noticed this aggressive behavior between them had stopped. Sally’s essential oils of choice were yarrow, violet leaf, rose and bergamot, all of which have, to varying degrees, anti-inflammatory and analgesic properties. Sally tended to move around stiffly, but after working with these essential oils she began to move around with speed and a new sense of playfulness. She started playing more often and in a more physical way.

Each primate has been affected in their own unique way by the use of essential oils and their zookeeper’s consistent work with them and the essential oils. This work has definitely added to their quality of life in captivity. I truly believe that working with essential oils is a noninvasive and natural approach towards working with animals in captivity.