The female generally remains close to the nest site, although not all actively defend the nest. She will scrape open the nest when the hatchlings are emerging. The incubation period lasts between two to three months, but may vary with nest temperature. Nests may be warmed by sunlight or by the heat of decomposing vegetation. Hatching may correlate with the onset of the rainy season.
Hatchlings tend to congregate together in groups called pods.
Pods may contain individuals from more than one nest, and they are often protected by the adult female's presence. Behavior Few good ecological studies have been made on the habits of M. niger . Despite having a range that overlaps with other species of caimans, M. niger appears to have its own ecological niche that enables it to coexist without too much competition. May through July marks a period of flooding in the Amazon, and during this time the populations of Black Caiman are dispersed amongst a wide expanse of its range. The dry season occurs from September through December, and at this stage water levels recede, flooded savannahs dry, and the Black Caimans are more densely congregated in the permanent lakes and rivers.