How Many Voices Sing in Kaziranga’s Swamps? Scientists Just Found Out

Beneath the tall elephant grass and floodplains that make Kaziranga National Park and Tiger Reserve world-famous, an equally vibrant aquatic world teems with fish, frogs, and reptiles. A rapid survey done between July and September 2025 by the park authorities in collaboration with scientists from the Wildlife Institute of India has brought to light this lesser-known side of Kaziranga's biodiversity.

The study counted as many as 77 species of freshwater fish, which is a high proportion of the 216 native fish species of Assam and a fair contribution to the Northeast's total of 422 indigenous varieties. Simultaneously, the park also supported 108 species of amphibians and reptiles, over half of all such species reported from the entire Northeast.

Experts say these numbers reaffirm Kaziranga’s status as a stronghold for native aquatic and semi-aquatic wildlife. The abundance of amphibians and reptiles, often seen as indicators of environmental health, also brings to light the contribution of the park in maintaining ecological balance.

Also Read: Kaziranga National Park's Kohora forest range reopens to tourists from today

The findings have been formally announced on November 2 at a function held at Kohora Convention Centre, where Environment, Forest and Climate Change Minister Chandra Mohan Patowary released the survey reports alongside the park's annual report and a poetry collection by Dr. Tapti Baruah Kashyap.

The Chief Minister of Assam, Himanta Biswa Sarma, has reacted to the findings on social media, terming Kaziranga "a vibrant emblem of Assam's natural heritage." According to him, the result underlines the efforts put in by the government in conservation and the commitment of the forest officials and the frontline staff.

Fishes of Kaziranga: The Treasure Hidden Beneath the Floodplains

The fish diversity survey recorded 44 species from 18 families, with Cyprinidae and Danionidae being the most dominant. Adding this to previous studies, Kaziranga’s fish diversity now stands at 77 unique species, placing it among the key freshwater biodiversity hotspots in the Brahmaputra basin.

Several species of conservation concern were recorded, including Wallago attu, which is Vulnerable, and Parambassis lala, which is Near Threatened. Other threatened and near-threatened species recorded in this study include Ompok pabda, Chitala chitala, Cirrhinus cirrhosus, Botia rostrata, and Clarias magur. All these play important roles in the aquatic food web of the park, serving as a support for predators like otters, fishing cats, and waterbirds.

The report further warns of growing threats from climate change, siltation, hydrological changes, and unregulated fishing, thus urging long-term monitoring and a stronger protection for Kaziranga's water systems. "Kaziranga's wetlands are as vital as its grasslands," the study says, emphasizing the value of the park as a natural laboratory for freshwater research.

Herpetofauna: Frogs, Lizards, and Snakes of Kaziranga

In a parallel study, the WII and Kaziranga authorities have jointly recorded as many as 31 species of amphibians and reptiles during the latest field survey-17 amphibians and 14 reptiles belonging to 19 genera and 14 families. Amphibians were most frequently encountered within forest trails and stream habitats, while reptiles were more abundant in wetter stream areas.

What made the survey so unique was the deployment of AI-based passive acoustic monitoring, an unobtrusive technique that recorded calls made by amphibians to identify species and monitor their breeding sites. This approach helped track diversity patterns across a range of ecosystems far more effectively than could be accomplished by visual observation alone. Putting together fresh and historical data, a total of 108 herpetofaunal species have now been confirmed from Kaziranga, of which threatened species include the King Cobra (Ophiophagus hannah), Assam Roofed Turtle (Pangshura sylhetensis), Asian Brown Tortoise (Manouria emys), and the critically endangered Nilssonia nigricans. Also, notable species listed only from Kaziranga include the striped caecilian (Chiromantis assamensis, Vulnerable) and the Kaziranga bent-toed gecko, Cyrtodactylus kazirangaensis (Data Deficient).