The frilled neck lizard or frilled dragon (Chlamydosaurus kingii) is an arboreal lizard noted for its flamboyant displays and its ability to run on its hind legs. They come down from the trees for feeding and breeding purposes. Frilled neck lizards are endemic to Australia and New Guinea.
The breeding season is the same as the wet season in frilled neck lizard habitat. It runs from October or November until February or March. Male frilled neck lizards use their frills not only as an aggressive display to frighten off potential predators and possibly rivals, but also to attract females. It isn't certain whether males with exceptionally large and colourful frills are more successful, but they certainly appear to use their frills as part of the courtship ritual.
After mating, the females lay about eight to 23 eggs in shallow, open nests, usually during November. The eggs incubate in the sun for two to three months before hatching. The sun provides a temperature of about 27.8 to 29.4 degrees Celsius, a range which is necessary for the eggs to hatch. Small temperature variations may decide the gender of the hatchlings, as is the case with many reptiles.
After the eggs hatch, the baby lizards stay together for mutual protection from predators for up to 10 days, although there is no parental care. Baby lizards have frills from hatching.
Female frilled necks mature at about 18 months old; males mature a bit earlier. Both sexes use their frills to give the appearance of being much larger than they are to frighten off predators. Male frilled neck lizards are territorial. How long a frilled neck lizard usually survives in the wild is unknown, but they have lived for at least 20 years in captivity. It is unlikely that many escape predators long enough to live to this age in the wild.
It is possible to breed frilled neck lizards in captivity but it requires specialised equipment. The adult pair need sufficient space, gravid females (i.e. carrying eggs) need a suitable nest site, the eggs need an incubator, and the hatchlings need a separate tank. Breeding frilled lizards is not a task for beginning reptile hobbyists.