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THE JOHNSTON’S CROCODILE

COMMON NAMES:
Johnston's crocodile, Australian freshwater crocodile, "Freshie", Johnston's river crocodile

LOCATION:
Northern Australia (Northern Territory, Queensland and Western Australia)

HABITAT:
Various permanent freshwater areas such as lakes, billabongs and swamps, plus less saline upstream areas of river systems and creeks. Generally not found near the coast, where the high salinity and competition with the more dominant Crocodiles makes the habitat far less favourable.

STATUS:
IUCN-International Union of Conservation of Nature (Low Risk Least Concern)     
Estimated wild population: 50,000 to 100,000
Summary: Healthy and considered recovered from historical population declines

APPEARANCE:
The Australian freshwater crocodile is a relatively small crocodilian which rarely exceeds 6-7ft. in the wild and can take as many as 30 years to reach! Females general reach a maximum size of 6ft. The shape of the snout is unusually narrow and tapering, lined with numerous sharp teeth. The body colour is light brown with darker bands on the body and tail.

DIET:
The long and slender shape of the snout, like that of the gharial, suggests a primary sourse of food is fish. Larger individuals may take a sit-and-wait hunting strategy, snatching prey up with a lightning-fast sideways movement of the head. It rarely feeds during the dry season because of a lack of prey availability.

BREEDING:
Males reach sexual maturity around 3.5ft. in length, females only slightly smaller. Courtship occurs in the early months of the dry season (around May) and nesting generally occurs between July and September depending on geographic region. Females dig hole nests in sand embankments, exposed after the wet season water levels fall. Various lizards and feral pigs are major predators of eggs during this period, when neither parent guards the nest.. The female parents return at the end of the incubation period and wait for the neonates to begin calling. They may then carry the newly-hatched juveniles to the water in their mouths, although the nests will still hatch out without the female being present. Adult females stay close to and protect the small crocodiles.. Only 1% of these hatchlings will survive to reach maturity. In some years, early rains at the end of the dry season can destroy almost all the nests through flooding. Juveniles which survive to maturity have been found returning to the same breeding and nesting areas.

CONSERVATION:
Good population data exist for this species. Hunting has been less of a problem mainly due to the presence of ventral osteoderms in the belly scales of adults. Recently, invasive species such as cane toads have led to mortality of adults and presumably juveniles in otherwise healthy populations. Small-scale farming and ranching programs exist for commercial purposes, and monitoring and management studies which were initiated in the 1970s are still ongoing.