Freshwater Crocodile, Johnston's Crocodile, Johnstone's Crocodile  |  

Crocodylus johnstoni


A greenish-grey to brown crocodile, with darker markings. Snout smooth and narrow; teeth not obvious with jaw closed. Active primarily at night, but may be seen basking or swimming during the day. During the later dry season, females bury up to 21 eggs in a sandy bank. The temperature during incubation determines the sex of the hatchlings: temperatures below 30 degrees and above 32 produce all females; temperatures in between produce 70% males and 30% females. After 2-3 months, the young squeak as they begin to hatch. A female (not always their mother) will help to dig them free, and may carry them to the water in her mouth. Females attain breeding age at 9 years (at the earliest); males at 16 years. Seriously susceptible to the toxin of Cane Toads, and recent declines of 16-77% in populations are recorded. Mostly permanent freshwater, but sometimes estuarine areas. They are most common where Saltwater Crocodiles do not occur.

Government evidence of impact of climate change:

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  • IUCN Red List Assessment, Crocodylus johnstoni

    Potential other unquantified threats include a) nest predation by dingoes; feral pigs and feral dogs; b) nest availability due to weed invasion; erosion of nesting areas; water diversion for irrigation projects and land clearing; c) climate change and encroaching saline waters that may result in upstream areas; and d) Saltwater Crocodiles (C. porosus) inhibiting the expansion of C. johnstoni populations due to their larger size and competition for resources.