Self-medication in wild animals
Zoopharmacognosy is a term used to describe self-medication in wild animals to treat or even prevent disease. The idea of self-medication by animals was first introduced by ecologist Daniel Janzen in 1978. Unusual feeding habits were observed that raised questions about animals using the secondary metabolites in plants as antibiotics, laxatives, and even antidotes for previously consumed toxins (Raman & Kandula, 2008).
Parasites can undermine the overall fitness of a species (i.e. lowering of reproductive fitness, compromised immune systems) and affect survival rates. This parasitic pressure is believed to be one of the main selective factors that led animals toward the use of medicinal plants (Raman & Kandula, 2008). According to Clayton & Wolfe (1993), self-medication can be classified into four categories based on contact mode: ingestion; absorption, topical application and proximity. One example of proximal medication can be demonstrated by birds that weave insecticidal green vegetation into their nests to combat ectoparasites.
Several studies have been done to test the hypothesis of self-medication. Some of these behaviors of diet selection may be linked to cultural practices. Nevertheless, “selection of the same plant species or species of related plant genera by two sympatric ape species or between regional populations of great ape subspecies strongly suggests a common criteria of medicinal plant selection” (Huffman, 1997. P. 171).
Side note: one of my fellow classmates at the University of Edinburgh (hey Denise!) will be focusing on this topic for her thesis. Students don’t forget we have several online resources for you to research this and many other topics for your papers online and in the library. Check out our database searches here or read the full articles listed below to learn more on Zoopharmacognosy.
Clayton, DH and Wolfe, ND, 1997. The Adaptive Significance of self-medication. Trend in ecology & evolution. V.8. pp 60-63. Online. Available through web of science. [Accessed on 8/22/12]
Rajasekar Raman and Sripathi Kandula, 2008. Zoopharmacognosy: Self-Medication in Wild Animals. Resonance, 2008, Volume 13, Number 3, Pages 245-253. Online. Available through web of science. [Accessed on 8/22/12]
Huffman, Michael, 1997. Current evidence for self-medication in primates: A multidisciplinary perspective. American Journal of Physical Anthropology, V104 (25), pp 171-200. Online. Available through web of science. [Accessed on 8/22/12]