Crocodiles: Social life
The social lives of crocodiles is complex. Male Nile crocodiles establish and defend breeding territories adjacent to the water and courtship occurs in the water. As the females approach; the males roar with such intensity that their flanks vibrate throwing up clouds of spray from the water, and their jaws clap furiously. Mating lasts for a few minutes with the male clasping the female. Their jaws and tails become intertwined during copulation. The female excavates a hole in the bank close to the waterline and lays about forty eggs in several batches. She ensures that the eggs are buried so that temperature remains relatively constant to within 3ºC. Saltwater crocodiles build mounds of vegetation as a nest and sprays urine to cool it if it becomes to hot. The alligators occurring in the New World piles up rotting vegetation into a nest which is regularly turned over in order to provide the eggs with appropriate temperature and moisture conditions. Just before hatching the female Nile Crocodile waits and when she hears the pipping calls of the hatching babies she will scrap the earth away and will pick her young up and put them into a pouch at the bottom of her mouth and will transfer them to the water. The male will escort these baby crocodiles to a nursery area where they will remain for the next few months with the parents closely guarding them. The Crocodiles and its allies invest considerable parental care in the rearing of its young after their hatching. Many dinosaurs were also thought to invest in considerable parental care, since they built fairly elaborate nests out of mud which would have retained the young dinosaurs until they were large enough to climb over the perimeter of the nest edge.