Gharial (Gavialis gangeticus) Fact Sheet: Reproduction & Development

• Courtship begins in December. Mating occurs in January and February (dry season).
• Female communicates readiness to mate by pointing snout upward.
• Bulbous knob on male's snout thought to be important in breeding. May act as visual identification for female, or as resonator of sound; see Vocalizations.
• The mating pair may stay under water for up to 30 minutes.
• Reproduction cycle determined by hormones as well as day length and rainfall.

• Occurs in March and April, between cold winter months and monsoon.
• Same approximate sites used each season.
• Females dig pitcher-shaped holes in steep, sandy river banks at night with hind feet.Eggs deposited, then covered with sand.
• Sometimes trial nest holes are dug before egg deposition.
• 1-10 m (3- 33 ft.) from water's edge, about 50 cm (20 in.) deep.
• Nest may be layered with sand in between.
• Female guards nest, but male does not.

Eggs

• Clutch size: 12 - 100 eggs, but usually in the range of 28 to 60 . Number of eggs corresponds to size of female.
• Egg size: Largest of any crocodilian species, 100-160 g (3.5 - 5.6 oz).
• Incubation: Temperature dependent – 53-94 days (incubation period shorter when temperature is higher). Female stays nearby for the duration.

Hatchlings

• Size: weight 75-130 g (2.6 - 4.6 oz), length 325-392 mm (12.8 - 15.4 in).
• Female does not bring the hatchlings to water in her mouth, as observed in other crocodilians.
• Group together, near the mother, for protection. Female protects hatchlings for several weeks, but will allow male to approach. Male does not actively protect hatchlings, but stays close and will carry them on his back.
• The sex of hatchlings is not determined by genes, but by temperature during incubation. Higher temperatures result in a higher percentage of males.

Adults

• Sexual maturity: Females ~3 m (9.8 ft) long at 10 years of age; males ~3.5 m (11.5 ft) long at 13 years of age; dependent on size more than age.
• Large knob at the tip of the rostrum in males begins to develop at about 10 years of age.

Wild populations

• Not reported
• Late maturity and large size suggests a long life span (Whitaker 1982; Nawab 2013)

Managed care

• No AZA estimates

See Threats to Survival.

The unusual bulbous snout of adult male gharials may be used in courtship or possibly longer distance communication.

The sound produced is modified into a buzzing (rather than hissing) sound.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Bustard (1980a)
Grenard (1991)
Martin & Bellairs (1977)
Ross (1989)
Whitaker & Basu (1982)