Zoopharmacognosy is the ability of some animals to know,
seek out and use certain plants for their medicinal value to cure what ails them.
This definition is my own because so far I haven't been able to find an
"official" dictionary definition. The earliest use of the word I've found was
in 19921.
Zoopharmacognosy is a relatively new field of study, so there is as yet no
exhaustive body of research on the topic. However, this has not stopped
Barnes & Noble from publishing a book about it.2
My own interest was drawn to to the subject by an article in
Die Welt4 which cites the following
anecdotal evidence by researchers observing primates:
- An orangutan, obviously suffering from a headache, held his head and went
over to a certain plant and ate some of its flowers. He seemed to be better within
an hour. At another time, when the researcher himself was suffering from a
headache, he bravely followed the ape's example and found his headache abating
soon afterward.
Another pair of researchers, one of them Michael Huffman, currently the
biggest name in zoopharmacognosy, observed a female chimpanzee who withdrew from the
group because she was suffering from diarrhea. She sought out a mjonso tree,
normally shunned by the chimpanzees because of its bitter and poisonous leaves
and bark. This time, however, she peeled some of the bark from a twig, chewed on
the pith and swallowed the juice. The next day the chimp was back to normal.
An analysis of the substances in the mjonso tree juices revealed 13 hitherto
unknown substances with antibacterial, antiparasitic and even antitumor
effects.3 It turns out the plant is valued by the African
locals for its over 25 medicinal properties.
-
Sometimes animals eat plant components for their physical properties rather than
their chemistry. Chimpanzees are frequently observed to eat the bristly leaves of
certain plants, swallowing them unchewed. These leaves have no nutritional value
and pass the digestive system crinkled but intact. But closer examination of
the leaves shows that they often trap parasitic worms from the animals' intestines
on their bristles. Some evidence for the conscious use of these leaves is found
in the fact that only sick chimpanzees eat the leaves, and mostly after the
beginning of the rainy season, when the number of parasitic larvae and the danger
of infection are at a maximum.
Other sources5 quote similar discoveries about primates
and other animals, including bears, turtles and even a porcupine. Study of
primates shows that knowledge about beneficial plants is passed on from parents
to young during the long course of their upbringing. How other species acquire
this knowledge is still a subject undergoing investigation.
References
- Rodriguez, E. and R.W. Wrangham. 1992. Zoopharmacognosy: Medicinal plant
use by wild apes and monkeys.
Paper presented at the 1992 American Association for the Advancement of Science
(AAAS) meetings. Chicago, Illinois.
- Engel, Cindy. Wild Health. Barnes & Noble, January 2002.
- http://veederandld.20m.com/greports/2501b.html
- http://www.welt.de/daten/2002/04/20/0420med327251.htx
- http://jinrui.zool.kyoto-u.ac.jp/CHIMPP/CHIMPP.html