Would a bush frog by any other name click as loud? Apparently yes, if the latest reassessment of the taxonomic status of three frogs in the northeast — Raorchestes kempiae, Philautus namdaphaensis, and Raorchestes manipurensis — is anything to go by. Considered three different species for the longest time, the latest study says, that the three frogs are not distinct but the same species.
P. namdaphaensis and R. manipurensis are now officially two “junior synonyms” of R. kempiae.
The scientists came to this conclusion after extensive study, including analysing their advertisement calls, apart from field surveys in northeastern states of Meghalaya, Manipur, Mizoram, and Arunachal Pradesh from 2019 to 2024 which included morphological comparisons as well as molecular analysis.
According to the corresponding author and general secretary of conservation NGO Help Earth, Jayaditya Purkayastha, R. kempiae was first described in the early 1900s, followed by P. namdaphaensis in 1985 and R. manipurensis in early 2000s. “The studies were not as holistic and nobody showed interest in following up and they continued to be considered as distinct species,” he says. He adds that polymorphism (physically or behaviourally different forms) in the species has misled the scientists into thinking they were different species.
The latest genetic tools as well as bioacoustics have, however, helped the scientists conclude that there are hardly any qualities that separate them. Since, according to international naming rules, the earliest name takes priority, R. kempiae, described first in 1919, is now the official name with the other two considered synonyms that will no longer be used indepedently.
This change also affects the assessment of the species’ risk of extinction. Earlier, R. manipurensis was listed in the IUCN Red List as “data deficient” since little was known about it, and P. namdaphaensis was listed as vulnerable for it was thought to occupy only a small area. The latest study, however, shows that R. kempiae has a much wider range than previously believed. “We found it across large parts of Northeast India and also in Bangladesh, Myanmar, and China, from low hills (50 m) up to 1,400 m elevation. Its total range now covers about 210,678 km², including several protected areas,” the paper states. Due to its wide distribution and the number of known populations, the paper recommends that the species, which is now listed as critically endangered be reassessed and categorised as least concern on the IUCN Red List.
Banner image: The latest taxonomic assessment found that Raorchestes kempiae, P. namdaphaensis, and R. manipurensis are the same species of a bush frog and would officially be called Raorchestes kempiae. Image courtesy of the Department of Zoology, Mizoram University.
