Equal Rights for Parasites!

Words by Rachel Nuwer

Reporter, Audubon Magazine

Published June 27, 2011

Trypanosomiasis, or African sleeping sickness, has influenced the distribution of people and animals across an entire contient. Credit: Flickr ILRI

They burrow under the skin, forming a painful, pulsing lump as they consume the host’s flesh from within. They lay their eggs in unsuspecting nests to ensure their large, greedy young thrive while other nestlings starve. They paralyze their prey so their offspring can enjoy a helpless, still-living snack. They lodge themselves in their victims' brains, driving the unfortunate creature to suicidal madness. They are parasites, and they deserve love, too!

Need some parasitic inspiration? Check out this beautiful, mind-blowing video on a parasitic, brain-controlling fungus that keeps jungle communities in check.

Ok, ok. So maybe parasites aren’t the most lovable group of animals around. But according to some scientists, they are entitled to just as much conservation attention as any lion, elephant, or other large, sexy beastie. Though they may seem the stuff of nightmares, parasites actually comprise the majority of species on earth, outnumbering non-parasitic animals by as much as 50 percent. At least 76,000 parasitic species exploit the minds, organs, reproductive strategies, and bodily fluids of nearly 45,000 vertebrate hosts, from squirrels to warblers. And all of these interactions add up: parasites play critical roles in their environments, driving evolution of their host species and keeping would-be-runaway populations in check. Though feelings of disgust are justified when watching a botfly larvae being tweezed out of some poor girl’s head, parasites’ overall effect on ecosystem is often positive.

Conservationists have suspected for years that many of their colleagues still aren’t on board the parasite love boat. Research published in Biological Conservation clarified this point with a recent survey of conservation textbooks. A couple parasite-adoring scientists scored any mentioning of the critters as ‘positive,’ ‘negative,’ or ‘neutral’ in 77 English language conservation textbooks from 1970 to 2009. For example, if a textbook referred to parasites only in light of the threat they play to agriculture, humans or animals, it received a ‘negative’ score. ‘Neutral’ scores were given to texts that described parasites only from an ecological or evolutionary standpoint rather than passing any judgment, and ‘positive’ scores were reserved for those texts that specifically mentioned parasite’s environmental value or the need to conserve them. An overwhelming 72 percent of the textbooks portrayed parasites as threats to the environment or did not mention them at all. Only 15 percent of the books contained even a single sentence portraying parasites as lifeforms worthy of conservation value.

Still not convined? Another cool video showing how birds help spread zombie parasite snails.

So what’s so worrisome about this trend? For starters, the conservation textbooks under scrutiny are the very ones used to educate young minds entering the field. If students are never introduced to parasites as a group warranting more than disgust and eradication, then parasites will never rise out of the pool of apathy and disdain in which they’re largely pigeonholed today. The number of parasites occupying our planet is daunting, but our knowledge and understanding of them is embarrassingly scant. The only way to begin amending that is to give these amazing—albeit creepy—creatures the attention they deserve.