The Gharial — Guardian of the Terai's Rivers
A gharial in a misty, reed-lined river in the Dudhwa landscape.
A fish-eating crocodilian found nowhere else on Earth, a twenty-kilometre stretch of the Girwa, and a newly documented population in an unprotected river.
The gharial (Gavialis gangeticus) is a fish-eating crocodilian found only in the river systems of the northern Indian subcontinent. It is listed as Critically Endangered on the IUCN Red List [1].
On the Girwa river in Katarniaghat Wildlife Sanctuary it survives as one of very few wild breeding populations, confined to about twenty kilometres of river below the Girijapuri barrage [2][3]. A 2023 survey also found gharials in surprising numbers in the unprotected Ghaghara downstream. The researchers suggest they are young animals carried out of the sanctuary when the barrage gates open [4].
The gharial is a sensitive measure of a river's health. It needs deep, flowing channels, clean sandbanks and plenty of fish. Where those disappear, so does the gharial.
A crocodilian built for fish
Everything about the gharial's shape points to its diet. Its long, slender snout, lined with fine interlocking teeth, sweeps sideways through the water to catch fish. That is a very different strategy from the heavy-jawed mugger crocodile.
Adult males develop a bulbous growth at the tip of the snout called the ghara, after the earthen pot it resembles, which gives the species its name. Gharials leave the water mainly to bask and to nest. Females dig their nests in exposed sandbanks, so the state of those sandbanks directly controls breeding [1][3].
A species brought to the edge
The gharial's decline across its range was steep. Mongabay-India, drawing on published estimates, reports that wild numbers fell from an estimated 5,000 in the 1940s to fewer than 200 by 1976 [3]. Surveys in 1973–74 found only 50 to 60 animals in India [1].
India's response from 1975 included a crocodile conservation project and new sanctuaries. Katarniaghat Wildlife Sanctuary was one of five sanctuaries set up between 1975 and 1982 [3].
Eggs were collected from the wild and incubated, and the young were reared and released. Gharial eggs from Katarniaghat went to the Kukrail Gharial Rehabilitation Centre in Lucknow for hatching and rearing [3]. By 1991, about 12,000 eggs had been collected nationally and more than 5,000 juveniles released, 3,500 of them in the National Chambal Sanctuary. Central funding for the programme was withdrawn that year [3].
Releasing captive-reared animals is not the same as recovering a wild population. Many released juveniles do not survive. The real test is whether wild females nest successfully and their young survive to breed, year after year.
The Girwa and the barrage
The Girwa is a channel of the Karnali, which flows south out of Nepal and joins the Ghaghara system. In Katarniaghat its gharials are hemmed in. According to Mongabay-India, the Girijapuri barrage, built in 1976, confined them to about twenty kilometres of river [3].
The barrage gates are opened every year for maintenance and during the monsoon. Young gharials can be swept downstream through them but cannot easily return. That keeps recruitment into the Girwa population low [3].
The river itself has also changed. Around 2010 a natural shift in the Karnali's channel upstream in Nepal reduced the flow down the Girwa [3]. With less water, vegetation spread over the sandbanks. A 2017–2019 study found that where open sandbars had turned into woody cover, the number of nests fell by more than 40 per cent [3].
Making room to nest
The sanctuary's response has been practical. Vegetation was cleared from nesting areas from 2019, and artificial sandbanks were built in 2020 [3].
Nest counts on the Girwa rose from 19 in 2019 to 36 in 2022, with a hatching success of 93 per cent in 2022. The Girwa population was estimated at more than 70 gharials that year [3]. These are encouraging, dated results from a managed site. Whether they are sustained will depend on river flows, flood timing and continued protection.
The 2023 Ghaghara survey
In 2023 a team led by Gaurav Vashistha tested a simple idea. If juveniles are being swept out of the Girwa through the barrage, they should turn up downstream in the unprotected Ghaghara [4].
- The 2023 count. On 26–27 February 2023 the team travelled about 100 kilometres of the Ghaghara, from the Girijapuri barrage to Chahlari Ghat, by wooden ferry boat, covering roughly 50 kilometres a day. They counted 84 gharials at 29 locations, about 0.84 per kilometre, many of them juveniles and none of them adult males [4].
- The 2021 count. An earlier survey by Singh and colleagues had counted 174 gharials further downstream, from Chahlari Ghat to Ayodhya [4].
- What the totals mean. Together the two surveys documented 258 gharials along about 219 kilometres of river. That is roughly four times the number in the Girwa, and the authors take it as support for the dispersal hypothesis [4].
These counts come from two different years and two different teams, so they are not a single estimate of the population at one moment. The authors also note that breeding in the Ghaghara had not yet been confirmed [4].
The threats they identify in the unprotected river are:
- flow regulation by the two upstream barrages
- agricultural use of the riverbanks
- small-scale fishing, which the authors did not consider severe enough to harm gharials directly [4][2].
Their recommendation is an integrated approach. Forest, revenue and irrigation departments would work with local communities to protect both the Girwa–Kaudiyala rivers inside the sanctuary and the Ghaghara outside it, backed by long-term monitoring [4].
The river beyond the gharial
The same waters support other animals. When flow in the Girwa dropped, Mongabay-India reports, a small resident population of Gangetic river dolphins moved into the neighbouring Kaudiyala channel, which had more depth and flow [3]. Mugger crocodiles, turtles, otters and fish-eating birds also depend on these channels. A river managed only for one species, or only inside a sanctuary boundary, will not keep them all.
Why it matters
The gharial is one of the world's most distinctive reptiles and one of its most threatened. Katarniaghat holds one of its few breeding strongholds. The Ghaghara survey shows that what happens downstream, outside any protected area, may decide whether the young bred in the sanctuary survive.
What this story tells us about Dudhwa today
Dudhwa Tiger Reserve is as much a river landscape as a forest. At Katarniaghat the health of the gharial depends on barrage operations, upstream flows from Nepal, sandbank management and the livelihoods of fishing and farming communities downstream. Watching a gharial basking on a Girwa sandbank is seeing the visible end of all those connections.
In closing
The gharial has survived dams, nets and a near-collapse of its numbers. In the Terai its future rests on a twenty-kilometre stretch of protected river and on a much longer river beyond it. The newest science suggests the species may be more widespread here than anyone recorded. Whether that becomes a recovery will depend on giving the rivers room to stay alive.
Questions
Where can gharials be seen in the Dudhwa landscape?
Gharials live in the Girwa river within Katarniaghat Wildlife Sanctuary, which is part of Dudhwa Tiger Reserve. The population is largely confined to about 20 km of river below the Girijapuri barrage, and a 2023 study also recorded many gharials in the Ghaghara downstream.
How many gharials live in Katarniaghat?
The Girwa population was estimated at more than 70 gharials in 2022. A 2023 study counted 84 gharials along 100 km of the Ghaghara below the barrage. Combined with a 2021 count of 174 further downstream, that made 258 gharials along about 219 km. These figures come from different years and are not a single population estimate.
What is the ghara on a gharial?
The ghara is a bulbous growth that develops on the tip of the snout of adult males. It resembles an earthen pot, or ghara, which gives the species its name.
What threatens gharials in the Terai?
The main threats are altered river flows from barrages and upstream channel changes, the loss of open sandbanks for nesting, agricultural use of riverbanks, and fishing pressure. Many of these threats lie outside protected-area boundaries.
Sources
- San Diego Zoo Wildlife Alliance Library. Gharial (Gavialis gangeticus) Fact Sheet: Population & Conservation Status (citing the IUCN Red List assessment by Lang et al., Critically Endangered). https://ielc.libguides.com/sdzg/factsheets/gharial/population
- Conservation Leadership Programme. "Study confirms precarious gharial stronghold in northern India." 23 January 2024. https://www.conservationleadershipprogramme.org/media-centre/news-post/study-confirms-precarious-gharial-stronghold-in-northern-india/
- Mahale, Sneha. "The gharial attempts a second comeback with help from the Katarniaghat Wildlife Sanctuary." Mongabay-India, 31 May 2023. https://india.mongabay.com/2023/05/the-gharial-attempts-a-second-comeback-with-help-from-the-katarniaghat-wildlife-sanctuary/
- Vashistha, G., V. Ranjan, D. Singh, S. S. Ugemuge, A. D. Badhawan and P. Gupta. "Status of the Critically Endangered gharial Gavialis gangeticus in the upper Ghaghara River, India, and its conservation in the Girwa–Ghaghara Rivers." Oryx 58(3) (2024): 336–339. https://doi.org/10.1017/S0030605323001485
How we handle evidence: documented facts are cited above; traditions, disputed accounts and figures we could not verify are labelled as such in the text. Read our approach.
