Shillong – In a remarkable breakthrough for biodiversity research in India, scientists from the Wildlife Institute of India (WII) have documented 13 previously unknown species of amphibians in the Northeast, highlighting the region’s rich and largely unexplored natural heritage. The discoveries, which span multiple states, underscore the ecological significance of Northeast India as part of two global biodiversity hotspots and offer new opportunities for conservation efforts in this ecologically sensitive area.

The newly identified species were documented across Arunachal Pradesh, Meghalaya, Assam, Mizoram, Nagaland, and Manipur. Of the 13 species, six were found in Arunachal Pradesh, three in Meghalaya, and one each in Assam, Mizoram, Nagaland, and Manipur. The discoveries were made over a five-year period between 2019 and 2024, as part of a comprehensive research study funded by the National Geographic Society and supported by the Meghalaya Biodiversity Board.

The new species belong predominantly to the genus Raorchestes, commonly known as bush frogs. Among the species discovered in Arunachal Pradesh are Raorchestes eaglenestensis, R. magnus, and R. nasuta, while Meghalaya yielded species such as R. lawngtalaiensis, R. barakensis, and R. narpuhensis. Other species identified include R. boulengeri, R. monolithus, and R. khonoma, demonstrating the taxonomic diversity within the region.

The study represents a significant advancement in the taxonomic documentation of amphibians in India. Led by Bitupan Boruah, a PhD scholar at WII, the research team included herpetologist Dr. Abhijit Das of WII and Dr. Deepak Veerappan, associated with the Natural History Museum in London and Newcastle University, UK. The collaborative nature of the study reflects an integration of local expertise with global scientific resources, enabling a thorough analysis of the region’s amphibian fauna.

One of the notable aspects of the research is its multi-pronged approach to species identification. The team employed a combination of acoustics, genetic analyses, and morphological assessments to differentiate the new species from previously known ones. This integrative methodology allowed the researchers to identify subtle distinctions in calls, physical traits, and DNA sequences that are often overlooked in conventional surveys. The study also revisited century-old museum specimens from the India-Burma region, housed in natural history institutions abroad, which helped clarify long-standing classification ambiguities. By re-examining these historical collections alongside contemporary field data, the researchers were able to fill significant taxonomic gaps and provide a more accurate understanding of species distributions.

Sampling for the study covered 81 localities across eight states, including 25 protected areas. This extensive fieldwork not only led to the discovery of new species but also enabled the team to revise the distribution maps of previously known bush frogs. As part of this comprehensive review, four previously described species were synonymized, reflecting updated taxonomic understanding. The result of this effort is a notable increase in the known bush frog species in India, from 82 to 95, reinforcing the Northeast’s status as a global hotspot for amphibian diversity.

The new discoveries have been formally published in the latest volume of the journal Vertebrate Zoology. According to the researchers, these findings are particularly significant because they resolve longstanding uncertainties surrounding the tiny “tik-tik” bush frogs, which are renowned for their distinctive high-pitched calls. These frogs, often small and elusive, have historically been challenging to study due to their cryptic behavior and limited visibility in dense forest habitats. The current research provides much-needed clarity on species identification, distribution, and evolutionary relationships within this group.

Beyond expanding the catalog of known amphibians, the study has important conservation implications. Northeast India, which encompasses part of the Eastern Himalayas and the Indo-Burma region, is characterized by a complex mosaic of ecosystems ranging from tropical and subtropical forests to montane grasslands. These habitats are increasingly under threat from deforestation, infrastructure development, climate change, and human settlement. By documenting species diversity and clarifying taxonomy, the study provides crucial baseline data for conservation planning. Accurate species identification is essential for assessing the conservation status of these frogs, many of which may be highly localized or vulnerable to habitat disturbances.

The study also emphasizes the need for continued exploration and monitoring of amphibian populations in Northeast India. Despite the discovery of 13 new species, researchers believe that a significant number of amphibians in the region remain undocumented, particularly in remote or inaccessible areas. The integration of genetic analyses, field observations, and historical museum data is expected to remain a vital tool for uncovering hidden biodiversity.

Experts note that amphibians, including bush frogs, are key indicators of ecosystem health. Their sensitivity to environmental changes, including pollution, habitat fragmentation, and climate variability, makes them critical for understanding broader ecological dynamics. The identification of new species not only enriches scientific knowledge but also highlights the urgency of habitat protection measures. Conservation strategies informed by rigorous scientific research can help safeguard these species while maintaining the ecological balance of forest ecosystems.

The collaboration between Indian and international researchers in this study underscores the importance of global scientific cooperation in biodiversity research. With institutions like the Natural History Museum in London contributing expertise and resources, the study demonstrates how international partnerships can enhance the scope and accuracy of taxonomic research. Furthermore, funding from organizations such as the National Geographic Society enabled sustained fieldwork and advanced laboratory analyses, which are essential for the discovery and validation of new species.

The researchers have also highlighted the importance of local community involvement in conservation efforts. Indigenous and local communities in Northeast India possess traditional ecological knowledge that can complement scientific approaches. Engaging these communities in monitoring, habitat protection, and awareness programs can contribute to long-term conservation outcomes while ensuring that biodiversity remains an integral part of regional livelihoods and culture.

In conclusion, the discovery of 13 new amphibian species in Northeast India represents a major milestone in the study of Indian herpetology. The research not only increases the number of known bush frog species from 82 to 95 but also fills critical gaps in taxonomy, distribution, and ecological understanding. With robust methods combining acoustics, genetics, morphology, and historical specimen analysis, the study exemplifies the rigorous approach required for modern biodiversity research.

By documenting these new species and revising the distributions of existing ones, scientists have provided valuable data for conservation planning, ecological monitoring, and future research. The findings underscore the extraordinary biodiversity of Northeast India and highlight the urgent need to preserve its unique ecosystems. As more discoveries are made and conservation measures implemented, the region may continue to reveal new facets of its rich amphibian heritage, reinforcing its global significance as a biodiversity hotspot.