Gharial (Gavialis gangeticus)

French: Gavial Du Gange
Spanish: Gavial Del Ganges
KingdomAnimalia
PhylumChordata
ClassReptilia
OrderCrocodylia
FamilyGavialidae
GenusGavialis (1)
SizeMale length: 5 - 6 m (2)
Female length: 3.5 - 4.5 m (2)
Top facts

The gharial is classified as Critically Endangered (CR) on the IUCN Red List (1), and listed on Appendix I of CITES (3).

The gharial (Gavialis gangeticus) is one of the largest crocodilians (a group that also includes crocodiles, alligators and caimans) with the narrowest snout of any species (4). The common name comes from the bulbous nasal appendage of the adult male, which resembles an Indian pot called a 'ghara' (5). The difference in the physical appearance between the sexes is unique to this species of crocodilian and is accentuated by the larger size of the male (2). Furthermore, unlike other crocodilians, the gharial has relatively weak legs and when fully grown is unable to raise its body above the ground on land (6).

Historically, the gharial was found in India, Pakistan, Nepal, Bangladesh, Bhutan, and Myanmar but is now extinct in most of these countries. The remaining gharial populations are restricted to India and Nepal and are highly fragmented (2) (5).

Probably the most aquatic of the crocodilians, gharials are found in the calmer, deep areas of fast-flowing rivers (6).

The distinctive narrow snout of the gharial is a superb adaptation for catching prey underwater. By providing very little resistance to water, it enables the gharial to whip its head sideways through the water to snatch fish with its small, razor-sharp teeth (2) (7). Although adults feed primarily on fish, juvenile gharials sustain themselves on a vast array of invertebrates (5).

Adult females, which reach maturity and become sexually receptive at around ten years old, are defended in harems by individual males (5). Although its precise function is poorly understood, it is thought that the male’s bulbous ghara may be a visual sex indicator, sound resonator or bubbling device utilised during courtship (6). Nesting occurs during the dry season when the females drag themselves onto dry land to excavate holes into which around 40 large eggs are buried (2) (5). The eggs are naturally incubated in the nest hole but the female remains near the nest to guard it from predators such as pigs, jackals, lizards and mongooses. After around 70 days when the hatchlings are ready to emerge, they call out from inside the eggs, alerting the mother to dig the eggs out of the nest hole. While the gharial does not display the crocodilian habit of transporting hatchlings in its jaws, the young stay with their mother for several weeks to several months (2).

The gharial came incredibly close to extinction in the 1970s, but a long-term captive breeding and re-introduction program was instrumental in improving the species status in the wild over the following decades. Despite these efforts, between 1997 and 2006, the wild population declined by 58 percent from 436 to just 182 breeding adults (1). Habitat loss and degradation poses the biggest threat to this species’ survival as the human population explosion of the Indian subcontinent continues to encroach on the river systems where it is found (5). Dams, irrigation projects, sand mining and artificial embankments have all encroached on the gharial’s habitat, reducing its range to just two percent of what it was (1). In addition, fishing removes important food sources and can cause clashes with fishermen leading to accidental or deliberate death. Eggs are collected for medicinal properties and adult males are hunted due to the belief that the snout has aphrodisiac effects (5).

Gharial population levels reached a catastrophic low in the 1970s prompting a massive rescue campaign (4). Restocking programmes involving captive breeding and ranching (wild eggs reared in captivity and then re-released) were established in India in 1975 and Nepal in 1978, and these worked to gradually bring this species back from the brink of extinction (5). However, in recent years the population has suffered another devastating decline, and in 2006 less than 200 breeding adults remained in the wild (1). The current decline indicates that no matter how many gharials are released into the wild, habitat degradation and hunting need to be prevented to ensure the species’ survival. Consequently, the focus of current conservation efforts is moving away from captive breeding programmes towards other initiatives such as the protection of gharial habitat, enforcement of the species’ protected status, and the education and involvement of local people in the species’ conservation. At the forefront of this is the Gharial Conservation Alliance, an international organisation of individuals dedicated to saving gharials from extinction (2).

To find out more about the conservation of gharials see:

 

Authenticated (6/5/03) by Adam Britton, Crocodilian.com.
http://www.crocodilian.com

  1. IUCN Red List (December, 2008)
    http://www.iucnredlist.org
  2. Gharial Conservation Alliance (November, 2008)
    http://www.gharialconservation.org
  3. CITES (October, 2002)
    http://www.cites.org
  4. Ross, R.P. (1998) Crocodiles: Status Survey and Conservation Action Plan. Second Edition. IUCN/SSC Crocodile Specialist Group, IUCN, Gland, Switzerland and Cambridge, UK. Available at:
    http://www.flmnh.ufl.edu/natsci/herpetology/act-plan/plan1998a.htm
  5. Crocodilian Species List: Gavialis gangeticus (June, 2002)
    http://www.flmnh.ufl.edu/natsci/herpetology/brittoncrocs/csp_ggan.htm
  6. Whitaker, R. and Basu, D. (1983) The gharial Gavialis gangeticus, a review. Journal of the Bombay Natural History Society, 79: 531 - 548.
  7. Burnie, D. (2001) Animal. Dorling Kindersley, London.