New research is trying to discover why some animals have been used more in traditional folk medicine than others. Researchers in Brazil investigated what life history and ecological traits were correlated with the use of wild mammals in traditional medicine. As there is little evidence that the animal products used in these medicines work better than a placebo would, the question is why the animals, and their body parts were chosen in the first place.

The study, titled “A global analysis of ecological and evolutionary drivers of the use of wild mammals in traditional medicine” was authored by Borges, A. K. M., et al. and it was published in 2020 in the scientific journal Mammal Review. The researchers found 521 mammal species used to source ingredients to treat 371 ailments, mostly in Africa, Latin America, and Asia. They think that mammals are used more than other vertebrates because they are often targets for hunting, so, after removing their flesh, the rest of body parts (bones, scales, claws, horns, fats, and oils) are then used for these purposes. The hard parts of the bodies are most often used. 

The scientists found that large mammals are used to treat more diseases, likely because they have larger body parts from which make more compounds. These body parts may also be easier to process than the equivalent parts of smaller mammals. The most endangered species tend to be larger on average, which suggests that their exploitation for medicinal use may be a contributing factor to their threat of extinction that may have been overlooked. Among the species investigated in this study 155 are considered threatened (Vulnerable, Endangered, or Critically Endangered), and 46 are considered Near Threatened.

More closely related species are perceived to have similar medicinal benefits and are used to treat similar diseases. All this information can be used in predicting what species might become targets for medicinal use next, once the species currently sought become rarer.