Freshwater Crocodile
Freshwater Crocodile
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| COMMON NAME: | Freshwater Crocodile |
| LATIN NAME: | Crocodylus johnstoni |
| FOOD: | Juveniles feed on insects, crustaceans, and small fish. Larger and older crocodiles feed on the same things, as well as larger prey such as amphibians, reptiles, bats, large fish, and land mammals that come close to the water. |
| HABITAT: | They are found predominately in freshwater lakes, billabongs, swamps, rivers, creeks, and wetlands. |
| LOCALITY: | Queensland, Northern Territory, and Western Australia. |
| LENGTH: | Up to 2.4-3 metres. |
| BEHAVIOUR:. |
Australian freshwater crocodiles are one of the few species that can gallop on land, reaching speeds of 18 km/h. They have a life span of 50 years and can also be cannibalistic and will eat juveniles. They swallow stones to aide in digestion, and drink only freshwater, not saltwater. Juveniles are killed by the adults when food is scarce and are also eaten by black kites, whistling kites, turtles, and large fish. Gould's monitor lizards, sand goannas, and feral pigs also keep the numbers down by destroying 80% of Australian freshwater crocodile nests. Habitat loss to farmland is also a major threat. |
| DEVELOPMENT: |
Sexual maturity for females is reached at 11-14 years, for the males 16-17 years with the breeding season being from September to October. Nests are dug in the river bank by the females, and are generally dug 15 m away from the water's edge and are 12 cm deep. Anywhere from 4-21 eggs are laid, and they hatch after an incubation period of 6-10 weeks. The temperature of the nest determines the sex of the juveniles: 31-31 °C — males, above and below that mostly females. When the eggs are ready to hatch, a female (not necessarily the parent) digs out the nest and crushes the eggs to release the juveniles, even though they have an egg tooth and could get out themselves. The juveniles sometimes get injured by her sharp teeth as she carries them to the water's edge. Less than 1% of the eggs laid will become mature Australian freshwater crocodiles. |
| DESCRIPTION: |
Australian freshwater crocodiles have unusually narrow, tapering snouts with a mouth lined with 68-72 sharp teeth. The fourth tooth on either side of the bottom jaw is larger than the others, and can be seen when the mouth is closed, fitting into a notch on the upper jaw. The eyes have a special clear eyelid called a nictitating membrane, which protects the eyes while underwater. They have strong legs with clawed, webbed feet and an incredibly powerful tail. The skin is light brown in colour, with dark bands on the body and tail and sometimes on the snout. |
