Gavial information

The Gavial, Gavialis gangeticus, is a crocodile-like reptile recognized on its long and narrow snout. It made a promising recovery in the 1980s and early 1990s but is now once again listed as Critically Endangered on the IUCN Red List of Threatened Species.  

Based on molecular genetic evidence, Janke et al. placed the Gavial and the False Gavial in the same family in 2005.  

Gavial taxonomy

Kingdom:      Animalia
Phylum:         Chordata
Class:            Reptilia
Order:           Crocodilia
Family:          Gavialidae
Genus:           Gavialis
Species:         Gavialisgangeticus

Gavial conservation status

Gavialisgangeticus is listed as Critically Endangered on the IUCN Red List of Threatened Species.

It was uplisted from Endangered to Critically Endangered in 2007. It is the only crocodilian that has been uplisted in this manner. The estimated wild population consisted of 200 individuals or less in 2005/2006. The distribution of this species is extremely fragmented and there has been an estimated 96% reduction from historical distribution.

Well into the 20th century the Gavial was common throughout its range, but by 1970 the species was in serious decline. Nine protected areas were formed in India and captive raised Gavials were released in cooperation with captive breeding and ranching programs. The wild population in India slowly began to recuperate and was eventually estimated at 1500 adults, plus roughly 100-200 specimens living in the remainder of the species range. 

Within the last decade, the Gavial has once again become threatened with extinction due to a combination of multiple factors. The main threats are habitat loss (primarily due to human encroachment and sand mining), pollution and entanglement in fishing nets.

Gavial range

The Gavial is today believed to remain in India and Nepal only, while the populations in Bangladesh, Bhutan, Burma/Myanmar, and Pakistan are believed to be extinct or nearly extinct.

In parts of its range, the Gavial co-exists with the Mugger Crocodile (Crocodylus palustris) or the Saltwater Crocodile (Crocodylus porosus).

Gavial habitat

The Gavial prefers calm parts of deep, fast moving rivers.

Gavial mobility

The Gavial is a highly aquatic species that isn’t suited for moving around on land. It will leave the water to bask in the sun, and females dig their nests in dry riverbanks, but aside from this the Gavial is rarely seen out of the water. Adult Gavials can not lift their bodies clear of the ground and can therefore only engage in belly-sliding, not high-walk. It can however slide quite fast when it has too.

In the water, the Gavial is exceedingly agile even compared to other crocodiles. It uses it large, laterally flattened tail to produce locomotion, and its extensively webbed rear feet are also helpful. The outer toes are two-thirds webbed, while the middle toe is one-third webbed.  

Gavial size and appearance

The Gavial resembles a crocodile but has an elongated, very narrow snout. The older the Gavial gets, the more narrow its snout becomes. The earliest examples of these creatures diverging from the other crocodilians are from the late Cretaceous.

The Gavial is one of the largest now living crocodilians in the world. Males frequently reach a length of 5 metres (16 feet) with occasional specimens exceeding 6 meters (20 feet). The heaviest Gavials weigh about 2200 lbs (1000 kg), but most specimens stay around a more modest 1500 lbs (680 kg).

Adult Gavials are normally dark olive while young specimens sport a paler shade of olive, with dark brown spots or cross-banding.

The Gavial has 106-110 teeth.

How large is the largest Gavial?
According to the Guinness Book of Animal Facts and Feats, the largest known Gavial measured 7 m (23 ft) and was shot in the Kosi River of northern Bihar in 1924.

Once upon a time, Gavialoidea species were much more numerous and diverse than they are today and one of these species, Rhamphosuchus crassidens, is believed to have reached a length of 15 meters (50 feet) or more.

How long is the Gavial's snout?
The snout length of a Gavial is 3.5 to 5.5 (depending on age) the breadth of the snout base. 

Gavial feeding and diet

Young Gavials are known to catch a lot of different prey, such as insects, larvae and small amphibians. Adults are much more specialized, feeding almost entirely on fish. Some individuals have also been seen scavenging.

The long and narrow snout of the Gavial is ideal for snapping up fast moving fish since it creates very little resistance in the water. When feeding, the Gavial uses its light snout to perform a fast lateral side-to-side snatching movement underwater and once the fish is caught the crocodilian can easily hold it with its numerous needle-shaped teeth – even when the fish is slippery and twisting. Gavials are often seen using their bodies to corral fish against river banks where they will be easier to catch.

Since the Gavial has such a light and narrow snout it has far less mechanical strength in its skull and jaws than most crocodiles and alligators and will therefore not attack large prey.

Gavial breeding

Female Gavials become sexually mature at a length of roughly 3 meters (10 feet); a length rarely attained by females younger than 10 years. One male will guard a harem consisting of several females. On the tip of his nose, he has a bulbous growth called ghara (the Hindi word for “pot”), which acts as a visual lure for catching the attention of females. He can also use his ghara to produce a resonant hum during vocalization and to form bubbles. These bubbles are believed to be important for the Gavial mating ritual but their exact role remains unknown. 

Gavials mate in November-January while the nests are excavated and the eggs laid in March-May when the dry season has made sandy river banks available for digging. It is always the female Gavial who excavates the nest. The clutch size varies from 30-50 eggs and incubation will take place for roughly 85-90 days. Gavial eggs are the largest of any crocodilian species, weighing 160 grams.

The female covers the eggs carefully after laying them and will also protect her young for a few days once the eggs are hatched. There is however no record of a Gavial helping young to reach the water; perhaps because their jaws and their needle like teeth aren’t very suited for carrying hatchlings. 

Gavial facts

Gavial facts # 1
The name Gavialis gangeticus is derived from both Hindi and Latin. Gavialis comes from a Hindi word for crocodile: ghariyal, while the word gangeticus means “of the Ganges” in Latin.

The Hindi word ghariyal comes from the word ghara which means pot, an allusion to the swelling around the nostrils that you can see on male Gavials. 

Gavial facts # 2
Within its native range, the Gavial is known under many different names such as Bahsoolia, Chimpta, Ghariyal, Lamthora, Naka, Nakar, Mecho kumhir, Shormon, Thantia, and Thondre. In the English language it is chiefly refered to as Gavial, Garial, and Gavial, but the names Fish-eating crocodile and Long-nosed crocodile also occurs.

Gavial facts # 3
Despite being one of the largest crocodilians in the world the Gavial is not considered a threat to humans. Its narrow jaws are so highly adapted to catching and devouring small fish that it can not overtake and swallow large prey. To gain speed and agility in the water, the Gavial has given up the robustness and immense force that makes crocodilians such as the Saltwater crocodile so dangerous to humans.

Jewellery is sometimes found in the stomach of Gavials and this has given it a reputation of being a man-eater, but the presence of jewellery is most likely a result of Gavials scavenging on corpses, e.g. incompletely cremated bodies in the River Ganges. Just like many other crocodilians the Gavial is also known to actively ingest hard object (primarily stones) to aid digestion.

Gavial facts # 4                    
In 2008, over 100 Gavials were found dead in the Chambal River in India. The cause remains unknown, but the dead animals showed gout-like symptoms and tests of the carcasses have suggested the possibility of metal pollutant poisoning.

Gavial facts # 5
The decline in Gavial populations have been linked to a decline in fish catches, since there are no longer sufficient amounts of Gavials to keep the predatory fish populations in check.