American Crocodile - Breeding

Breeding

American crocodiles breed in late fall or early winter, engaging in drawn-out mating ceremonies in which males emit very low frequency bellows to attract females. Body size is more important than age in determining reproductive capabilities, and females reach sexual maturity at a length of about 2.8 m (9.2 ft). In February or March, gravid females will begin to create nests of sand, mud, and dead vegetation along the water's edge. Nest location is crucial, and with the correct amount of vegetation, the eggs will develop within a small temperature range. Because sex determination is temperature-dependent in crocodilians, slight aberrations in temperature may result in all-male or all-female clutches, which would possibly harm the health of the population. About one month later, when it is time to lay, the female will dig a wide hole diagonally into the side of the nest and lay 30 to 70 eggs in it, depending on her size. After laying, the female may cover the eggs with debris or leave them uncovered. The white, enlongated eggs are about 8 cm (3.1 in) long and 5 cm (2.0 in) wide and have a number of pores in the brittle shell. During the 75- to 80-day incubation period, the parents will guard the nest, often inhabiting a hole in the bank nearby. Females especially have been known to guard their nests with ferocity. But in spite of these precautions, crocodile eggs sometimes fall prey to raccoons, foxes, skunks or other scavenging mammals. Crocodilian eggs are somewhat brittle, but softer than bird eggs. Young of this species hatch after 75–80 days.

This species exists mostly in tropical areas with distinct rainy seasons, and the young hatch near the time of the first rains of the summer (July–August), after the preceding dry season and before the bodies of water where they live flood. In this stage of development of their young, mother crocodiles exhibit a unique mode of parental care. During the hatching process, when the young crocodiles are most vulnerable to predation, they will instinctively call out in soft, grunt-like croaks. These sounds trigger the female to attend to the nest, uncovering the eggs if they have been covered. Then she will aid the hatchlings in escaping their eggs and scoop them up with her mouth, carrying them to the closest water source.

The hatchlings, which are 24 to 27 cm (9.4 to 11 in) in length, have been reported to actively hunt prey within a few days of hatching. It is not uncommon for the mother to care for her young even weeks after they have hatched, remaining attentive to their calls and continuing to provide transportation. About five weeks after hatching, the young crocodiles disband in search of their own independent lives. Most of them, of course, will not survive, being preyed upon by various raptorial birds and larger fishes. Those that do survive the early stages of life will grow rapidly, feeding on insects, fish and frogs. Additionally, some young crocodiles reportedly will feed on each other.