A. mississippiensis
A. sinensis
C. crocodilus
C. c. apaporiensis
C. c. fuscus
C. latirostris
C. yacare
M. niger
P. palpebrosus
P. trigonatus

FAMILY:
CROCODYLIDAE

C. acutus
C. intermedius
C. johnstoni
C. mindorensis
C. moreletii
C. niloticus
C. novaeguineae
C. palustris
C. porosus
C. rhombifer
C. siamensis
M. cataphractus
O. tetraspis
T. schlegelii

FAMILY:
GAVIALIDAE

G. gangeticus

DICHOTOMOUS KEY
[German]

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NAME ETYMOLOGY:
> Gavialis is a corrupted derivation from the Hindi word ghariyal which is a name for "crocodile".
> gangeticus means "of the Ganges (River)", where -icus means "belonging to" (Latin)
> "Gavial" is a mis-spelling of the word "Gharial" (derived from the Hindi ghariyal) that refers to the ghara (Hindi for "pot") - a swelling around the nostrils of mature males used for communication (sound)

DISTRIBUTION:
[CLICK ON MAP FOR DETAILED RANGE]
Northern India subcontinent: Known populations exist only in India and Nepal. It is now considered very likely that historical populations in Bangladesh, Pakistan, Bhutan and Myanmar are extirpated.

Remaining populations in India are found in the Chambal River (<100 adults in National Chambal Sanctuary), Gitwa River (20-30 adults in Katernia Ghat Sanctuary), Son River (<5 adults in Son River Sanctuary), Mahanadi River (<5 non-breeding adults in Satkosia Gorge Sanctuary) and around 40 non-breeding adults in the Ken, Ramgenga, Yamuna and Brahmaputra rivers. Remaining populations in Nepal are found in Narayani/Rapti River (<10 adults in Chitawan National Park) and around 30 non-breeding adults in the Karnali, Babai and Koshi rivers.

HABITAT:
Riverine - gharials are more adapted to an aquatic lifestyle in the calmer areas of deep, fast-moving rivers. Sandbanks on these rivers are exposed seasonally, sometimes in different areas as the banks are moulded by the river over time. Gharials concentrate around these sandbanks during the dry season making them more vulnerable to disturbance. The gharial is poorly equipped for locomotion on land, and adults cannot lift their bodies clear of the ground. It usually only leaves the water to bask and nest, both of which usually occur on sandbanks.

STATUS:
     CITES: Appendix I
     IUCN Red List: 2007 update: uplisted to CR CRITICALLY ENDANGERED, formerly EN C2a, E (ENDANGERED)
     Estimated wild population:200 or less (based on 2005/06 information) with an estimated 96% reduction from historical distribution
Summary: Extremely fragmented distribution, deteriorating status in recent years and intense pressure from human activities makes the gharial one of the most endangered animals on Earth

APPEARANCE:
[click on image for enlargement]
Characteristic elongate, narrow snout, similar only to the false gharial (Tomistoma schlegelii). Variation in snout shape occurs with age (generally becomes proportionally longer and thinner with increasing age). The bulbous growth on the tip of the male's snout is called a 'ghara' (after the Indian word meaning 'pot'), present in mature individuals. It has several functions attributed to it: a vocal resonator with which the gharial can produce a loud buzzing noise during social behaviour, a visual stimulus for females during courtship, and an aid to producing bubbles also during courtship. The elongated jaws are lined with many interlocking, razor-sharp teeth - an adaptation to the diet (almost exclusively fish in adults). The gharial is one of the largest of all crocodilian species according to several reports, approaching C. porosus in terms of maximum size - males reach at least 5 metres in length, and occasionally approach 6 metres. Reports of 7 metre animals exist, but are unconfirmed and considered highly unlikely. The gharial is poorly equipped for locomotion on land as an adult - the leg musculature is not suited to raise the body off the ground to produce the 'high-walk' gait - being able only to push its body forward across the ground ('belly-sliding') although it can do this with some speed when required. It is, however, very agile in the water - the tail is well-developed and laterally flattened, and the rear feet possess extensive webbing.

DENTITION:
5 pre-maxillary; 23-24 maxillary; 25-26 mandibular
Total no. of teeth = 106-110

IMAGES:
[click on image for enlargement]

Side view of adult gharial head

Side view of adult gharial head

DIET:
The diet changes between juvenile and adult - the juveniles are well suited to deal with a variety of invertebrate prey such as insects, plus smaller vertebrates such as frogs. Adults, however, are almost exclusively fish-eaters, for which their jaws and teeth are perfectly adapted - the thin shape gives the snout low resistance in water, which is suited to fast lateral snatching movements underwater; teeth are ideally suited for holding struggling prey such as slippery fish. The slender jaws are precision instruments capable of deftly manipulating fish into position for swallowing. There have been accounts of larger gharials being more opportunistic and taking larger prey, including mammals, but this seems extremely rare if it happens at all, and may simply be explained by a gharial snapping at a nearby disturbance.

Gharials are not considered a threat to humans. They have occasionally been blamed for human fatalities, but there is no evidence to back this up. Human remains and jewellery have been found in their stomachs and were thought to validate this fear, but these are most likely to have been scavenged from the dead - the Hindi funeral ritual ends with the remains of the cremated body being sent down the river. Jewellery is possibly ingested in the same way that stones would be in order to be used as gastroliths - hard objects which aid in digestion.

BREEDING:
Females reach sexual maturity around 3 m in length (usually over 10 years old). Males guard a harem of several females. The mating period occurs for two months during November, December and into January. Nesting occurs in March, April and May (the dry season) where hole nests are dug into seasonally-available riverine sand banks. Between 30 and 50 eggs (average of 37) are deposited into the hole before it is covered over carefully. The size of the eggs in gharials is the largest for any crocodilian species, weighing on average 160 grams. After 83 to 94 days, the juveniles emerge, although the female has not been observed assisting the hatchlings to the water as in many other crocodilian species. This is perhaps because of the unsuitability of their jaws for carrying hatchlings, and also because of their needle-sharp teeth. However, protection of the young does occur around the nesting area for some time after hatching.

CONSERVATION:
The gharial is in serious trouble once more. In the first half of the 20th Century the gharial was common throughout its range, with an inferred population in the 1940s of between 5,000 and 10,000. By 1970, however, it was apparent that the gharial was in serious decline and this prompted scientific surveys to determine the extent of the problem. These were initially carried out by S. Biswas of the Zoological Society of India, and then extended into an India-wide survey conducted by Rom Whitaker. Full protection was granted in the 1970s in the hope of reducing poaching losses, although these measures were slow to be implemented at first. A total of 9 protected areas were established in India linked to both captive breeding and 'ranching' operations where eggs collected from the wild were raised in captivity (to reduce mortality due to natural predators) and then released back into the wild (the first being released in 1981). Over 3000 animals were released through these programs, and the wild population in India recovered to an estimated 1500 adults - with perhaps between one and two hundred animals in the remainder of its range (Pakistan, Bangladesh, Nepal).

Yet despite this recovery, surveys within the last decade have revealed that populations are once again in decline, and this time it is looking grim. Available habitat is being eroded, fishing and pollution are serious threats to both juveniles and adults, and populations have disappeared from many former haunts. By 2007 the gharial was once again elevated to the status of CRITICALLY ENDANGERED on the IUCN Red List. This is the first crocodilian species to have been re-listed in this manner.

The major threat at present is habitat loss due to human encroachment, sand mining and disruption of populations through fishing and hunting activities. Pollution is also suspected to be a serious factor, possibly to blame for a mass die-off of adults in early 2008. A historical problem has also been a lack of suitable release sites for any release programs. Gharial eggs are occasionally collected by local people for medicinal purposes, and males have been targeted for the aphrodisiac properties associated with the snout. They may also be snared in fishing (gill) nets and killed by fishermen. The decline in gharial populations have been linked to a decline in fish catches, as predatory fish (of no interest to the fishermen) form a major part of the crocodiles' diet.

The Gharial Conservation Alliance (GCA) was established in 2007 and comprises key gharial scientists, experts and stakeholders primarily in gharial range states. Starting with fund- and awareness-raising campaigns, it is coordinating research and conservation activities on remaining populations and habitats. Key priorities include protecting all remaining suitable habitats from illegal activities that threaten gharials, monitoring and research on current populations, addressing human impacts on gharials and riverine habitat, and establishing conservation programs with local communities.

MORE INFORMATION:
For more information on distribution and conservation issues for this species,see the CSG Action Plan resource.

SIGNIFICANT REFERENCES: