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The Remarkable Medicines Wild Animals Find in Nature

The “animals’ pharmacy” mainly aims at treating parasites and wounds using plants and insects

It turns out that many animals know how to alleviate some of their common health problems and we are only beginning to (officially) learn about it. Dolphins, for example:

Indo-Pacific bottlenose dolphins get skin conditions, too, but they come about their medication by queuing up nose-to-tail to rub themselves against corals. In the journal iScience on May 19, researchers show that these corals have medicinal properties, suggesting that the dolphins are using the marine invertebrates to medicate skin conditions.

Thirteen years ago, co-lead author Angela Ziltener (@DWAORG), a wildlife biologist at the University of Zurich, Switzerland, first observed dolphins rubbing against coral in the Northern Red Sea, off the coast of Egypt. She and her team noticed that the dolphins were selective about which corals they rubbed against, and they wanted to understand why. “I hadn’t seen this coral rubbing behavior described before, and it was clear that the dolphins knew exactly which coral they wanted to use,” says Ziltener. “I thought, ‘There must be a reason.’”

Cell Press, “Watch dolphins line up to self-medicate skin ailments at coral “clinics”” at Eurekalert (May 19, 2022) The paper is open access.

There was indeed a reason: The dolphins were stirring up the coral polyps which then released mucus which my help the dolphins with skin health and and treat infections: “It’s almost like they are showering, cleaning themselves before they go to sleep or get up for the day,” Says study researcher Angela Ziltener, who dived down to where the dolphins hang out to find out what was going on.

In one of many other such observations, a chimp mother was recently seen using an insect to ease
a bite wound on her offspring:

For the first time, researchers observed chimpanzees in Gabon, West Africa applying insects to their wounds and the wounds of others…

“In the video, you can see that Suzee is first looking at the foot of her son, and then it’s as if she is thinking, ‘What could I do?’ and then she looks up, sees the insect, and catches it for her son,'” Mascaro says. The Ozouga team started to monitor the chimpanzees for this type of wound-tending behavior, and over the next 15 months documented 76 cases of the group applying insects to wounds on themselves and others.

Cell Press, “Chimpanzee mother seen applying an insect to a wound on her son” at ScienceDaily (February 7, 2022) The paper requires a fee or subscription.

Just what the insect does for the chimp’s wound is unclear but cognitive biologist Simone Pika notes, “there have been studies showing that insects can have antibiotic, antiviral, and anthelmintic functions.” That may be but perhaps the main outcome will turn out to be pain/itch relief.

Elephants have been observed to use plants for medicinal purposes too. Researchers interviewed mahouts (work elephant riders) as to what the elephants did on their own that they had adopted as part of a care routine:

114 species [of plants] were recorded as being consumed by elephants during interviews with mahouts and forest outings with them to collect samples. Twenty species were identified as used by elephants in particular pathological conditions or physiological states. According to interviewed mahouts, the consumption of certain plants improves the health of the elephant. We observed clear convergences between the observations interpreted by the mahouts as self-medication behaviour from elephants and their own medicinal practices (for human and veterinary purposes).

Dubost JM, Lamxay V, Krief S, Falshaw M, Manithip C, Deharo E. From plant selection by elephants to human and veterinary pharmacopeia of mahouts in Laos. J Ethnopharmacol. 2019 Nov 15;244:112157. doi: 10.1016/j.jep.2019.112157. Epub 2019 Aug 12. PMID: 31415849.

Similarly, dogs self-medicate:

Anyone who has seen a dog eat grass during a walk has witnessed self-medication. The dog probably has an upset stomach or a parasite. The grass helps them vomit up the problem or eliminate it with the feces.

Joel Shurkin, “Animals that self-medicate” at Proc Natl Acad Sci U S A. 2014 Dec 9; 111(49): 17339–17341.

So do cats, likely for the same reasons:

And birds:

Some birds have started stuffing an unlikely material into their nests: cigarette butts. No, they’re not ne’er-do-well parents. On the contrary, they could actually be using the chemicals in the butts as medicine against parasitic mites, protecting their little chicks. It’s not as crazy as it seems as tobacco leaves contain chemicals that repel pests; tobacco juice and nicotine sprays can be used as garden pest control.

Researchers studied two bird species that are common in North America, house sparrows and house finches, and measured the amount of cellulose acetate, a synthetic fiber found in cigarette butts, present in their nests. They found that nests with higher levels of this fiber contained fewer parasitic mites. Additionally, the researchers placed unsmoked and smoked cigarette butts in bird nests and found that there were half as many parasites in the nests with smoked cigarettes than non-smoked cigarettes. Smoked cigarettes contain much more nicotine because the smoke has passed through them.

Elena Motivans, “Animals take medicine when they are sick: a few striking cases” at ZME Science (January 22, 2021)

The urban sparrows and finches could only have been doing this since the advent of rolled cigarettes. However, they may well have used a natural product instead beforehand.

Is medication use a sign of intelligence? That’s not clear. In the case of animals already known to be intelligent — dolphins, chimps, elephants, dogs, and cats, for example — we can assume that the ability to foresee and remember a benefit and to learn from others plays a role in turning an accidental discovery into a habit.

But what about insects? Take butterflies:

Take the monarch butterfly that lays its eggs on milkweed, which has antiparasite effects. “All we have to do is look at a healthy monarch butterfly and a sick monarch butterfly,” says Jacobus de Roode, assistant professor of biology at Emory University, who specializes in the beautiful creatures. “Now, a sick monarch butterfly is really affected by these parasites. The parasites bore little holes in the abdomen, and she will lose some of her bodily fluids and doesn’t feel good.” The changes in her physiology can change the way she responds to smells of the vegetation around her and she may have a genetic preference for these that would do her good.

Joel Shurkin, “Animals that self-medicate” at Proc Natl Acad Sci U S A. 2014 Dec 9; 111(49): 17339–17341.

And fruit flies:

When fruit flies sense parasitic wasps in their environment, they lay their eggs in an alcohol-soaked environment, essentially forcing their larvae to consume booze as a drug to combat the deadly wasps. The finding adds to the evidence that using toxins in the environment to medicate offspring may be common across the animal kingdom.

Emory Health Sciences, “Fruit flies force their young to drink alcohol for their own good” at ScienceDaily (February 13, 2022) The paper is open access.

These life forms are not thought to have much in the way of individual consciousness, relative to mammals and birds, so it is unclear how they acquire the skill, apart from genetic imprinting, to use plants as a defense against parasites.

The technical term for wild animals self-medicating with plants or insects is zoopharmacognosy. Not only do we have much more to learn about the “animals’ pharmacy” for its own sake but we may well learn something of value for human health too.

You may also wish to read: Why cats can remember other cats’ names. University of Kyoto scientists found that they can indeed remember, provided they live in the same household. The researchers are unsure exactly how cats remember other cats’ names. But that may not be a great mystery if we keep in mind what is involved. (Denyse O’Leary)

Denyse O'Leary

Denyse O'Leary is a freelance journalist based in Victoria, Canada. Specializing in faith and science issues, she is co-author, with neuroscientist Mario Beauregard, of The Spiritual Brain: A Neuroscientist's Case for the Existence of the Soul; and with neurosurgeon Michael Egnor of the forthcoming The Human Soul: What Neuroscience Shows Us about the Brain, the Mind, and the Difference Between the Two (Worthy, 2025). She received her degree in honors English language and literature.

The Remarkable Medicines Wild Animals Find in Nature