Gharial Gonservation

The gharial (Gavialis gangeticus) is one of the most endangered crocodilians in the world, found only in Nepal and India. This unique species is known for the male’s bulb-like structure at the tip of its snout, called a “ghara,” which gives the gharial its name. Currently, gharials occupy just 5% of their historical range and are divided into 14 subpopulations. Of these, only six are actively breeding, with the Chitwan population being one of the key breeding groups in Nepal. However, the breeding behavior of gharials in the wild is not well understood.

With support from the EDGE of Existence program by ZSL, CFN conducted a study on the reproductive ecology and behaviors of gharials in the wild. The project focused on monitoring the aquatic communication of male gharials, which produce a loud “POP” sound to attract females, patrol their territory, and guard their hatchlings.

The main objectives of this project were to:

– Determine the breeding population of gharials in the Rapti and Narayani River systems
– Study the mating, nesting, and guardianship behaviors of gharials
– Understand the acoustic communication of gharials in the Chitwan population
– Assess community perceptions of gharial conservation
– Identify the historical distribution of gharials in Chitwan

This research aims to provide a solid evidence base to support the conservation efforts for this critically endangered species.

For about four decades, nests from the wild have been collected for a captive rear and release program. Although Chitwan National Park hosts the largest breeding population of gharials in Nepal, the natural reproduction of these crocodilians is not well understood. To address this, we initiated a long-term monitoring program aimed at gathering scientific data and knowledge on:

– The breeding population of gharials in Chitwan National Park
– The number of nests laid each year
– The hatching success rate of nests and the total number of hatchlings produced annually

This ongoing study aims to build a comprehensive database over time. The goal is to estimate the wild breeding rate and determine whether natural reproduction can support the stabilization of the gharial population in Nepal.

With fewer than 900 adult gharials left in a few protected areas in Nepal and India, this species is one of the world’s most endangered crocodilians. Since the 1980s, conservationists have released hundreds of captive-bred gharials into Chitwan National Park, which is home to Nepal’s main population. However, the low survival rates of these released hatchlings have hindered the species’ recovery.

To stabilize the gharial population, natural recruitment (the process of hatchlings surviving and growing in the wild) is crucial. Therefore, CFN aims to understand several key aspects:

– How do hatchlings move and spread out from their nesting sites?
– What are the survival rates of hatchlings, yearlings, and juveniles?
– What are the main threats to these young gharials in the river?
– What is the natural recruitment rate based on the survival rates?

By answering these questions, the project hopes to enhance the conservation efforts for the critically endangered gharial in Nepal.