In most species of lizards, the life cycle begins with the lizard hatching from an egg, although a few species give birth to live young. Juvenile lizards then grow into adults without undergoing a metamorphosis that is seen in amphibian species. Adults mate and lay eggs and the cycle begins again. The time that it takes for each stage of the life cycle and the total life span of lizards varies by species.Most lizards, including iguanas, geckos and water dragons, lay soft, leathery eggs. In most species, females bury their eggs in holes and leave the eggs on their own. Some species will return to warm the eggs.
Incubation time varies. Frilled lizard eggs hatch in approximately 70 days while green iguana eggs hatch in 90 days.Hatchling lizards break open the egg with their egg tooth or caruncle. They remain in the egg for approximately 12 to 24 hours to absorb the remaining yolk before emerging from the egg.A few species of lizards, including the Solomon Island and blue-tongued skink give birth to live young.After hatching or birth, juvenile lizards are fully able to fend for themselves. In most species, lizard parents do not provide care or protection for the young. Juveniles grow into adults without any significant changes other than size.Once fully grown, lizards are adults and may begin mating. The mating process varies by species. For example, the frilled lizard mates during the wet season between October and March. Males attract females by spreading their frill. After mating, females lay 8 to 23 eggs. Females may lay up to two clutches each breeding season.Green iguanas begin mating when they are approximately 16 months old. Mating occurs during the dry season, usually in the fall. Males attract females with their colors and displays such as head-bobbing and push-ups. Females lay a clutch of 12 to 30 eggs.