The Titicaca water frog should be thankful that it looks a bit like a scrotum. Without its wrinkled appearance, the amphibian may not have scored a clickworthy nickname. And without a quirky name, news editors may not have paid as much attention when 10,000 of these critically endangered animals turned up dead on the shores of the Coata River in Peru.

Peruvian environmental authorities are investigating the deaths of as many as 10,000 frogs on Lake Titicaca. Image: SERFOR

Reports of the mass die-off began to surface earlier this week after news outlets picked up on a statement published by Peru's National Forestry and Wildlife Service (Serfor). Authorities had responded to claims from a local environmental group that dead frogs were washing up along the banks of the Coata River, a tributary that flows into the 8,372-square kilometre Lake Titicaca. Specialists were called in to investigate and were met with a grisly scene.

"Based on local residents' statements and samples taken in the days after the incident, it is believed that more than 10,000 frogs were affected over about 50km (30 miles)," the statement points out. This number is only an estimate, but even if experts missed the mark by a few thousand, the death toll would still be cause for concern.

The Titicaca water frogs' uniqueness doesn't stop at their resemblance to dangly bits. Weighing in at just under a kilogram (two pounds), the scrotum frogs of South America are amongst the largest in the world. They're also entirely aquatic and perfectly adapted for their lofty life in the highest altitude lake on the planet. Although that excessively flabby skin has earned them a less than flattering moniker, the amphibians actually rely on the skin folds to increase their breathing ability. That's right, they breathe through their skin (in this way, they differ from scrotums).

This odd jerking behaviour is actually how the Titicaca water frog breathes. By bobbing up and down, the frogs are able to move their large skin flaps, allowing them to absorb more oxygen from the water.

Sadly, like many of the world's unique species, the Titicaca water frog faces a number of threats, and it's likely that humans are to blame for the recent deaths. While news of the die-off may come as a shock to many outside of Peru and Bolivia, local animal activists are not very surprised. According to the Committee Against the Pollution of the Coata River, untreated sewage sludge is to blame. "Lake Titicaca used to be a paradise," local anti-pollution campaigner and vice president of the committee, Maruja Inquilla Sucasaca, told The Guardian. "Now we can't use the water and our livestock die if they drink it." 

Sucasaca was responsible for alerting authorities to the recent frog deaths, and she's frustrated by the apparent lack of action from local government in dealing with the pollution concerns. "The situation is maddening," she told AFP. "I've had to bring them the dead frogs. The authorities don't realise how we're living."

And raw sewerage may not be the only pollutant in Lake Titicaca that's affecting local wildlife. According to Roberto Elias, a US-based researcher from the Denver Zoo, who has been studying these unique frogs since 2010, runoff from mining operations in rivers surrounding the lake has caused levels of heavy metals in the water to spike. Previous studies show an abundance of arsenic, lead, mercury, cadmium, iron and zinc – a toxic cocktail that's likely to have dangerous consequences for amphibians in the area.

While Elias stresses that necropsies will have the final say in determining what happened to the frogs, he also suspects that a recent garbage clean-up in the river could have disturbed settled sediments, releasing contaminants that may have caused the sudden die-off.

Pollution is just one of many threats putting the wrinkly frogs in peril. Thousands of Titicaca water frogs are also hunted every year and shipped off to Lima, where they are skinned and blended with water, maca (a local tuber) and honey to make "frog juice" – an elixir that's consumed as an aphrodisiac. Many communities surrounding Lake Titicaca also eat the frogs, and gourmet restaurants catering to the tourist trade sometimes offer dishes featuring frog legs.

According to the IUCN Red List, the species has declined by as much as 80% over the last three generations. In an effort to help these numbers recover, a decision was made at a recent wildlife trade summit held in South Africa to add the water frogs to CITES Appendix I, a listing that offers maximum protection and prohibits all trade in the species.

So yes, the frogs are named after man bits, and, yes, we know it's tricky to say Titicaca without smirking just a little, but sadly this situation is anything but funny. Without intervention from the authorities to clean up the lake and regulate excessive harvesting, conservationists are concerned that we may end up losing the frogs forever.

Header image: Shutterstock