In what experts are calling one of the most significant zoological discoveries in India in over a decade, researchers have identified thirteen entirely new bush frog species across Northeast India. The breakthrough, published in the latest edition of Vertebrate Zoology, a scientific journal of the Museum of Zoology in Dresden, Germany, highlights the extraordinary biodiversity of India’s eastern Himalayan landscape and the urgent need to protect it.

The discovery is the result of years of intensive work by a team of Indian and international researchers. Scientists Bitupan Boruah and Abhijit Das from the Wildlife Institute of India (WII), together with V. Deepak from the Natural History Museum in the United Kingdom and Newcastle University, carried out extensive surveys across the region between 2016 and 2024. Over eight years, the team collected and studied 204 frog specimens from 81 locations spanning eight northeastern states: Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, and Tripura. Their findings reveal previously undocumented amphibian diversity in one of the world’s richest biogeographical zones.

Before this study, India was known to host 82 recognised bush frog species, of which just 15 were recorded from the northeast. With the addition of the newly described frogs, that figure has now significantly grown, marking a huge scientific milestone. “This is the highest number of vertebrate species described in a single publication in over a decade in India,” said co-author Abhijit Das of WII. He emphasised that such discoveries underline how much remains unexplored, even in areas previously assumed to be well-documented.

The northeastern region’s rugged terrain, heavy monsoon climate, and rich tropical forests create ideal habitats for diverse amphibian life. Yet, its inaccessibility has long kept parts of it away from detailed scientific inquiry. The team’s wide geographic sampling also allowed them to re-evaluate existing classifications. In addition to discovering new species, the study reassessed the distribution of already known frogs and even synonymised four earlier-described species — a major contribution toward resolving long-standing taxonomic uncertainties.

The largest cluster of discoveries comes from Arunachal Pradesh, where six new species were identified. Two of these were found inside the Namdapha Tiger Reserve, a globally recognized biodiversity hotspot located at the intersection of India, China, and Myanmar. One species each was also documented from the Eaglenest Wildlife Sanctuary and Mehao Wildlife Sanctuary. These findings reaffirm Arunachal’s reputation as one of India’s most biologically rich states, with habitats ranging from tropical lowlands to alpine heights, nourished by the Eastern Himalayan ecosystem.

Meghalaya, a state defined by its cloud forests and record-breaking rainfall, contributed three new species to the list. Each of these frogs has been named after the locality or inspiration connected to its discovery. The Narphu Bush Frog was identified in the Narphu Wildlife Sanctuary, the Mawsynram Bush Frog comes from Mawsynram — one of the wettest places on Earth — and the Boulenger Bush Frog has been named in honor of George Albert Boulenger, a pioneering British-era herpetologist whose work laid the foundation for amphibian science in South Asia. These names not only define place-based identity but also pay tribute to the scientific legacy intertwined with the region.

Assam, Nagaland, Mizoram, and Manipur produced one species each, with the Barak Valley Bush Frog being reported from the Barail Wildlife Sanctuary in Assam, a key conservation zone linking the biodiversity of the Northeast with Barak Valley ecosystems. Together, these discoveries indicate that important amphibian species continue to survive even in landscapes facing significant human-driven pressures.

Researchers involved in the project underscore that these findings are not just exciting scientifically but also carry urgent conservation implications. Das pointed out that uncovering so many new species from protected areas such as tiger reserves reveals how much remains unknown even within designated conservation landscapes. He added that the discoveries represent an important step in addressing three crucial global conservation challenges: the Linnean shortfall (unknown species going extinct before they are identified), the Wallacean shortfall (limited knowledge of species distribution), and the Darwinian shortfall (insufficient understanding of evolutionary relationships).

Each newly identified frog species also acts as an indicator of environmental health. Amphibians are among the most sensitive organisms to ecological changes because they depend on both terrestrial and aquatic conditions. Their declining populations are often early warnings of habitat degradation, pollution, or climate imbalance. Thus, cataloguing new frogs does more than expand scientific records — it deepens awareness of the delicate environmental balance sustaining life in one of India’s most crucial ecological corridors.

However, the researchers’ optimism is measured by concern. Their surveys documented widespread habitat threats across the northeastern states. Rural shifting agriculture practices, known locally as jhum cultivation — which involves clearing forest areas by burning vegetation — remain a major cause of deforestation. Expansion of cash crop plantations such as cardamom, the rise of linear infrastructure including highways and power lines, and mega dam construction across major river systems are collectively transforming landscapes at an alarming pace. These mounting pressures are shrinking safe breeding zones for sensitive species such as bush frogs, many of which are found exclusively in specific microhabitats with very narrow environmental tolerance.

The study strongly advocates prioritizing amphibian conservation in future developmental planning. It stresses that protecting the region’s endemic species — those found nowhere else on Earth — should be considered a national biodiversity responsibility. As Northeast India continues to integrate economically with the rest of the country and the broader South Asian region, the challenge will involve balancing ecological protection with human progress.

The discovery of thirteen new bush frog species thus stands as a testament to the richness of Indian wildlife and the tireless efforts of the scientific community to document and protect it. It reinforces that far from being biologically exhausted, the wild terrains of the northeast remain treasure troves of evolutionary history, waiting to be uncovered. The researchers hope their work will serve both as a celebration of this diversity and a call to action for stronger environmental safeguards.

With rapid environmental change sweeping across the region, the clock is ticking. The fate of these newly discovered amphibians — and countless others yet unknown — will depend on how quickly conservation measures can be strengthened and how effectively gaps in knowledge, policy, and protection can be bridged. In many ways, the discovery marks not an end but a beginning: the start of renewed efforts to safeguard India’s overlooked but indispensable species, hidden deep within its most enchanting and ecologically vital forests.