Juveniles remain close to the female for several months after hatching in a creche, staying in touch with acoustic calls. Major predators of the hatchlings include birds and fish, but the major cause of death is cannibalism by other, adult crocodiles. Maturity is reached more rapidly in captive animals, which grow more quickly as their food intake is much higher. Maximum size in males has been documented at around 7 metres, and over 1000 kg in weight, but 5 to 6 metres is a more realistic maximum size. Maximum age is at least 70 years, perhaps over 100 years old.
Growth generally continues throughout life, but is very slow in older animals.
Large crocodiles can be aged by the number of growth rings in their bones. Conservation Unregulated hunting occurred over 25 years and brought the population to the brink of collapse. Populations have shown a massive recovery throughout Australia, particularly in the Northern Territory, yet public opinion about crocodiles is still mostly negative. Concern over increasing numbers makes it critical to gain public support about crocodiles. This only works if proper controls are in place, otherwise illegal trade may be stimulated.