A new species of frog with bright red eyes and a quiet groaning call has been discovered in eastern Madagascar – but is already endangered because the forest patches where it lives are shrinking.
Known in English as the rugose forest frog, the new species, with crinkled brown skin dappled and streaked with fiery red, is only around the size of a thumbprint.
US and Malagasy scientists first came across it in 2015 while surveying patches of high-level evergreen forest near the town of Andasibe. As is common in discoveries of this type, it’s taken some time to have the new species formally confirmed and named.
“It was exciting as it was clearly a species not documented before, and wasn’t in any of the guide books,” Carl Hutter, researcher at the Louisiana State University Museum of Natural Science, told RFI.
Hutter discovered the frog while on a walk near their campsite, following a downpour.
The frog belongs to the genus or group of frogs known as Gephyromantis, which can only be found in Madagascar. Its specific name, marokoroko, is a Malagasy word that describes the frog’s wrinkled skin.
“We wanted to have a species name that resonated with the local people and would be descriptive in the Malagasy language to hopefully help in its conservation,” Hutter said.
It was also the first time the team’s Malagasy guides had seen the species.
After that first sighting in 2015, the team spent several years collecting specimens, capturing recordings of the frogs’ calls and studying its DNA.
It was finally declared a new species last week and featured in a paper published in the journal zoosystematics and Evaluation .
The frog, which has long fingers and toes, is not dependent on running water. Instead, it lives on the forest floor and reproduces in small puddles trapped in leaf litter.
The frog utters its call, which is described as “a heavily pulsed trill” or “groan” that is barely audible to humans, whenever it sits on the upper surfaces of leaves located a short distance above the ground after rain.
Each time the researchers approached them, the frogs would go silent. They had to put them inside plastic collecting bags and record their calls from around a metre away.
But there is a danger those calls could fall silent forever, thus the urgent need to safeguard nature and biodiversity.
Only two out of the four areas where the rugose forest frog is known to live are protected. These are the Andasibe-Mantadia National Park and Vohimana Special Reserve.
The other forest patches at Vohidrazana and Tavalobe are threatened by slash-and-burn agriculture.
The research team has categorised the frog as endangered, based on the International Union for conservation of nature’s’s criteria.
It’s likely there are more new species that exist in other unexplored parts of Madagascar, and field work to discover them needs to continue, Hutter said.
“We have a stronger argument for protecting areas when we know what species occur there.”
Mark Scherz, assistant professor of vertebrate zoology at the University of Copenhagen, said the rugose forest frog comes from a group that is poorly known because its members are so hard to find.
“It takes a combination of patience, skill, and a good amount of luck to find individuals of such species,” he said.
Scherz, who last year described a new species of diamond frog from northern Madagascar, was not part of the team that discovered this new species.
He said several new species of frog from frequently-visited areas of Madagascar had been catalogued. Scherz added that science still has a ways to go before it produces a full list, even of vertebrates, in the world’s biodiversity hotspots.
“How incomplete must our knowledge be of the smaller animals that are even harder to find, study, and describe?”