Conserving the Gharial: A Case Study

The gharial (Gavialis gangeticus) has to be the most instantly recognisable crocodilian in the world – and also the most endangered, being the first one to be re-categorised as “Critical” by the International Union for the Conservation of Nature in 2007.

With its characteristic long, thin snout, adorned in adult males with the protuberance that gives it its name – after the ‘ghara’, a local type of earthenware pot – gharials were once widespread throughout their range across the Indian sub-continent. In the 1940’s their numbers were put at 10,000 or more; the picture today is somewhat different. A survey of Nepal undertaken in 2008 found fewer than 100 individuals and their range has shrunk alongside their tumbling numbers, with this unique reptile now largely restricted to just four river systems in Bhutan, India, Pakistan and Nepal, with a few small populations in Myanmar.

Recent conservation initiatives in Nepal, however, look set to make a significant contribution to our understanding of this remarkable species and should ultimately help boost its long-term survival.

Captive Breeding

Like so many other of the world’s threatened wildlife, captive breeding programmes hold the glimmer of hope against extinction for the gharial and nearly 700 have been released into the Babai, Karnali, Koshi, Kali Gandaki, Narayani and Rapti rivers between 1981 and 2008.

Despite great successes with a range of species, however, breeding animals for re-introduction is not without its own difficulties, and successfully managing to rear a few of the creatures in the first place is only the beginning. Being able to assess the success of re-introduction projects can be a significant factor in planning further conservation strategies, but often once you have released animals back into the wild, it is difficult to know exactly how they are doing. With an animal such as the gharial which naturally favours deep, fast-flowing rivers, it’s a major problem.

In an attempt to get around it, a new initiative by Nepal’s Department of National Parks and Wildlife Conservation, with the collaboration and financial support of the WWF and the Critical Ecosystem Partnership Fund, is underway using the latest in radio-tagging. If successful, it will have both bolstered gharial numbers, and helped amass vital intelligence on their progress which could prove critical in planning for their future survival.

Reptile Radio

The underlying idea is very simple; by attaching radio-transmitters – each with its own individual frequency – to the crocodiles, it becomes possible to track their movements, once they have been released into their new homes. Known as Radio Frequency Identification (RFID) it’s the same technology that tracks valuable commercial shipments in transit – only now its attached to the scutes of a gharial’s tail, rather than a containerised load. Monitoring these transmissions will now give unprecedented insight into the lives and movement of re-introduced reptiles and could pave the way for further re-release projects in other parts of the gharial’s ancestral range.

The initial group of 14 radio-equipped animals were freed from an improvised holding pen at the Dumariya ghat on Nepal’s Rapti River in 2009, said to be the first release and monitoring project of its kind to be undertaken in the world.

Long-Term Conservation

Historically, hunting was the major threat to the species, but with the establishment of National Parks and the rise of effective national and international conservation law, today the hunter’s bullet no longer represents the danger it once did. In common with many creatures, the principal driver on the gharial’s extinction is now habitat loss, with the construction of dams, canals and barrages, along with sand-mining and changes to agricultural practice, threatening much of its original range. In addition, pollution across much of the waterways, coupled with over-fishing, have limited its natural supply of food. Fortunately, the water quality in Nepalese rivers is generally better suited to gharials than in many of the surrounding regions, making the current initiative a particularly important one. As Dr Antoine Cadi – one of the scientists responsible for fitting the radio-tags – commented, if these magnificent creatures cannot be saved in Nepal, the species will be that much closer to extinction.

Projects such as this one are important steps in conserving these animals, but clearly, more work is essential if the world’s most distinctive crocodilian is to avoid going the way of its dinosaurian relatives. Research, captive breeding and monitoring form one side of the equation; safeguarding gharial habitats and prey form the other. It’s an urgent issue but with luck, the knowledge and understanding gained from these Nepalese radio-tagged reptiles may make formulating a plan to save their kind that bit easier and future generations will be able to see the gharial for themselves.

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