Like other reptiles, the saltwater crocodile is oviparous, with females laying an average of 50 eggs per season. Incubation time roughly varies from two to four months. Temperature determines the sex of the embryos. Temperatures ranging from 88 to 91 degrees Fahrenheit lead to embryos becoming males, while colder or warmer temperatures produce females. The egg yolk provides a vital source of energy during the embryo's development.
Hatchlings measure about 1 foot and weigh 70 grams when emerging from the egg. However, within one or two years, young saltwater crocodiles are often longer than 3 feet. The hatchlings' first journey to the water is in the mother's mouth. Just before hatching, they make chirping sounds to attract the female's attention. Only a few hatchlings reach adulthood due to attacks from predators such as birds, fish and even adult crocodiles.
Juveniles remain close to their mother for almost a year after hatching, communicating with her and their siblings through a variety of sounds. Crocodiles are juvenile for 10 to 15 years. After this period of intense growth, juveniles reach sexual maturity and become adults. Juveniles feed on small prey such as insects, fish and crustaceans.
When sexually mature, saltwater crocodiles mate once a year. Males are often very territorial, and can feed on almost any animal, including monkeys, sharks, kangaroos, wild pigs and even buffaloes. Despite their name, saltwater crocodiles are often found in areas of brackish and fresh water, near estuaries. Adult males can adventure into the ocean to catch prey, swimming at a speed of 18 miles per hour. Although growth decreases drastically in sexually mature animals, saltwater crocodiles continue to grow throughout their long lives. Saltwater crocodiles can live as long as 90 years.