Want to be a wildlife biologist? Beware the eyeball leeches and chest maggots

Emma Hankinson travelled to Sumatra to study whether parasites common to dogs, cats and livestock were having an impact on wild orangutans; she contracted hookworms while there.

While following a troop of sooty mangabeys, monkeys found in the forests of Ivory Coast, Boston University primatologist Erin Kane walked face-first into a tree. Almost instantly, her eye became red, itchy and watery, but she went on following her monkeys. After about half an hour more of discomfort, she got nervous and asked her field assistant to take a look.

He found a tick embedded on the inside of Kane's eyelid.

"Poor Richard," Kane said of the assistant on that 2012 expedition. "He was also the person who squeezed botflies out of my armpit for me because I couldn't get the leverage quite right."

Primatologist Erin Kane was unlucky enough to get a tick on the inside of her eyelid. Photo / Getty

This, ladies and gentlemen, is a day in the life of a wildlife biologist. While scientists are often pictured as lab-coat-wearing beaker brokers, many researchers still venture out into the natural world to observe animal behaviour, take stock of human influence on ecosystems and generally add to our understanding of the planet and its inhabitants. Unfortunately, the pursuit can sometimes leave them itchy, bleeding or full of holes.

Adriana Lowe, a behavioral ecologist at the University of Kent, opened this literal can of worms recently by asking her fellow scientists for their most repulsive parasite stories on Twitter. The online community did not disappoint. Let's start with the bloodsuckers.

Most of us are familiar with leeches - those wriggly, segmented worms infamous for latching onto any ankles and legs that wander through a swamp. But did you know that not all leeches are aquatic, or that many of the species that inhabit southeast Asia can crawl across the ground and even climb trees in their quest for hot blood?

Tiger leeches are especially enterprising, said Anton Sorokin, a graduate student at East Carolina University studying evolutionary ecology and behavior. In Borneo, where he once travelled to assist in a study of fruit-eating mammals, Sorokin says the bloodsuckers drag themselves up to waist-high leaves and grab onto whatever walks past. The team he was part of suffered leech bites everywhere, from behind their ears to inside their belly buttons. On several occasions, Sorokin even caught leeches nosing around his private parts.

"Luckily, it's such a sensitive area that I knew immediately that it was happening and would drop what I was doing and extract the leech before significant progress was made," Sorokin said. But he said he soon realized that "there was no choice but to learn to deal with it and, sooner than I would have expected, the leeches turned from unnerving horrors to mere nuisances."

Leeches are used in medical therapy but are a nuisance when trekking through the jungle. Photo / Getty

Even still, Sorokin once counted as he picked leeches off his skin, clothing and backpack. The total: 102. That's a lot of nuisances.

But leeches are nothing compared to a nasty case of leishmaniasis he contracted while looking for endangered El Oro parakeets in the foothills of Ecuador's Andes. For the uninitiated, leishmaniasis is a disease caused by protozoan parasites. Humans acquire the nastiness after getting bitten by an infected sand fly. Untreated, leishmaniasis can create large, festering wounds, like the one Sorokin developed on his leg.

After two doctors in Ecuador told him the weepy and growing lesion was just an infection, Sorokin insisted on a biopsy, which confirmed his suspicion that it was leishmaniasis. Treatment included reporting to a nearby hospital daily for giant, painful shots.

"Occasionally the nurses there would also scrub out the hole. Sometimes this involved hydrogen peroxide or rubbing alcohol, and I can honestly say it must have been the most painful thing I have ever experienced," said Sorokin, who still sports a large scar on his shin from the ordeal.

Other scientists tell similar horror stories.

Biologist Lorraine Wilson got the plague from a tree rat. Primatologist Eve Holden came down with a super itchy and contagious fungal infection that caused doughnut-shaped circles all over her skin. Anthropologist Michelle Ann Kline contracted a yeast infection on her scalp that made her hair fall out in patches. It also smelled like bread dough, she said in a tweet.

In 2010, Emma Hankinson traveled to Sumatra to study whether parasites common to dogs, cats and livestock were having an impact on wild orangutans. Because hookworms and the like pass on their progeny through faeces, it was Hankinson's job to go into the forest and find orangutan poop so it could be tested. Unfortunately, she became part of the cycle when tiny red squiggles started to appear on her shoulder.

"The hookworm left the trail on my skin whilst migrating through the epidermis," Hankinson said. "However, the larvae cannot complete their life cycle in a human, and become trapped in the epidermis, and die after several weeks."

Bat biologist Dave Hemprich-Bennett is also familiar with hookworms. He got 10 or more of the buggers while collecting guano in Borneo as part of his Ph.D work - including one that caused his right eye to swell up like he'd been sucker-punched.

"I also had one living in my butt cheek, but I didn't take any photos of that," Hemprich-Bennett said. (And for that, we thank him.)

But of all the creepy crawlies the scientists of Twitter described, perhaps no story is as squirm-worthy as the tale of Ben Garrod and the mango flies.

Botfly maggots extracted from a man's elbow. Photo / Getty

Garrod is a broadcaster for the BBC, as well as an evolutionary biologist at Anglia Ruskin University in the United Kingdom. But for a time, he ran a large chimpanzee conservation programme in western Uganda, which meant spending long periods of time deep in the forest.

One night, Garrod recalled, he felt "an annoying little itch" on his chest while drifting off to sleep. A quick look with the flashlight revealed a bit of redness - probably a sun rash, he thought. But some of the spots felt tender, almost as though they could be popped like a pimple.

"Like any normal human being, I squeezed one of the spots, making it burst," he said. At this point, Garrod grabbed his glasses for a clearer look. He immediately regretted the decision.

Peeking halfway out of his chest was a white, wriggling mango fly maggot.

"It was like the lamest recreation of 'Alien' ever," Garrod said.

Mango flies lay their eggs on an animal's fur or a human's clothes. Proximity to warmth makes the eggs hatch, at which point the teeny, tiny larvae burrow into the animal's skin, where they grow and develop into truly terrifying little beasts. Even the creature's official name, Cordylobia anthropophaga, nods at this behavior. It means "human eater."

Garrod said the flies are usually found deep in the forest and therefore don't bother people very often, but they can absolutely torture other animals. (Many videos online show veterinarians extracting full-grown maggots from dogs and cats by the hundreds. But be warned, such videos are extremely difficult to stomach.)

Back in the forests of Uganda, Garrod had been bracing himself for this moment. "It was the one thing I was dreading," he said. "Cobras, mambas, lions, chimps, no problem! But not maggots under my skin!"

Other field researchers had warned him to iron his clothes vigilantly because high heat kills the eggs. He'd made it for nearly a year without issue, heating an iron on hot coals in his field camp each day.

After extracting the maggot and swabbing the hole in his chest with iodine - which caused a white hot pain Garrod says he can still feel 10 years later - the biologist settled back into bed, proud for having survived his first real parasite. Then he felt an itch on the other side of his chest.

"I had a whole field of the little bastards!" Garrod said.

Garrod admits to still over-ironing all of his clothes to this day, even though he's living in the United Kingdom. But other than that, he's over the trauma.

"It doesn't put us off," he said of the flies, hookworms, malaria and other side effects field researchers endure. "It just gives us interesting stories to tell."