#‘Scrotum frog’ is essential to Lake Titicaca region and must be saved, experts say

Despite its undignified moniker, the “scrotum frog” is critical to the South American ecosystem.

Conservationists say this funny frog is a key part of their work in the Lake Titicaca region, between Peru and Bolivia, where the frog can grow up to 8 inches long and 2 pounds in weight, making it the world’s largest water frog. Its ample lichen-green-hued skin has folds and creases — hence its nickname — which give it an upper hand at oxygen intake.

And as an “indicator species,” the prevalence of its population is considered a key guide to ecological health in the 3,200-square-mile lake in the Andes.

The complexity of the region and elusiveness of the frog makes its population difficult to track, but the International Union for Conservation of Nature reported a decline of between 80% and 90% from 1994 to 2004 — and the health of the lake has worsened since, according to local experts.

In 2019, the IUCN changed the frog’s status from “critically endangered” to simply “endangered,” while concluding that inconsistent data coming from separate research efforts has contributed to an overall unclear picture of the species’ current conditions.

“It is evident that the population is declining at an accelerated rate,” they wrote in their assessment, last revised in September. “However, a lack of systematic surveys across the lake makes it difficult to accurately assess population sizes and rate of decline.”

They outlined a long list of threats to the species, including urban wastewater, chemicals used in agriculture, dams, climate change, aquafarming, novel diseases and invasive species.

This void of information prompted Bolivia’s Natural History Museum to launch a collaborative effort to save the overlooked amphibian. The research campaign, with support from the United Nations Development Programme and the Global Environment Facility, will allow scientists from Peru, Bolivia, Ecuador and the US to study the frog’s aquatic habitats more fully. Their findings will also help inform future environmental-conservation legislation in the region, according to local water authorities.

In 2016, some 10,000 scrotum frogs perished from unconfirmed causes, though local media outlets speculated that waste mismanagement may have played a role, based on reports of sludge and sewage waste at the site of the deaths.

The same year, biologists at the Denver Zoo became the first in North America to acquire the species, and hatched some 200 tadpoles in their lab. Those same US researchers will now join those from universities and museums across western South America to continue the work to save the scrotum frog.