It requires a century or so for dragons to reach sexual adulthood, when the rudimentary wings of the males become more brightly patterned, and the females turn an alluring tone of golden yellow on their undersides. At that time the females also begin to exude a musky odor from special glands under their chins, and males are able to detect these odors through hundreds of miles of water or dozens of miles of air. The mating season is in the late spring, and it is then that dragons are most likely to be seen or heard by humans, as they become so preoccupied with mating that they lose much of their habitual wariness.

The mating displays of dragons no doubt vary among the several different species and have been observed by only a few trained biologists. Among the flying dragons, both sexes perform synchronized aerial displays while facing one another, and the male performs looping or falling leaf shows and spectacular dives from great heights, finally pulling out and zooming over the female's head while she watches from the ground. Displays in the flightless species are obviously much less spectacular, but also involve the exposure of the brilliantly patterned wings, which are waved about as the male jumps and leaps. This mating display often lasts for hours, as the male dances his way around the female. Great circular impressions are made in the ground from his continuous wild movements. The origin of these circular markings, or roundeleys, has often been mistakenly attributed to prehistoric human activities. The female dragon meanwhile thumps her tail on the ground, in time with the dance like movements of the male. Traditional display grounds are usually barren hillsides or even mountaintops, where the visibility is unrestricted and where the light of the morning sun strikes first. The display begins well before dawn and continues until the sunlight is so intense that the animals must retire to darker places. Most actual mating probably occurs before sunrise or during twilight hours. Dragons use traditional display grounds for centuries. In England, these circular display grounds are often found in particular geographic alignments, or dragon-leas, which connect various hilltops (dragon weyrs) and stone circles. These stone circles have been erected by early dragon-worshipping cults, to help commemorate traditional display sites, and perhaps to attract new dragons to the area. A few similar stone circles have also been found in Montana and other parts of the mountainous American West, suggesting that similar dragon cults probably existed in these places as well. Displays go on at the dragon arenas for several weeks, until the dragoness has been fertilized. Then she retires to her weyr to await the laying of her eggs. In the large flightless dragons of Europe and America, the female lays a small clutch of three or four eggs, which are about the size of grapefruits, pure white, and shiny as pearls. As the young dragon embryo grows within, the egg gradually turns to a beautiful golden hue, looking like true gold. By the time the female dragon is ready or her first mating flight, she is generally a beautiful adult beast who has acquired the wisdom of the most learned wise woman, and received intensive instruction in all the fields of dragon know ledge. She sets out on this flight alone, but is joined by the males who wish to mate with her. She ends up at the center of a swarm of several hundred fully developed male dragons. The flight of dragons - which can easily be spotted due to its sheer size - travels towards the destination chosen by the Dragon Father for the union. Winged dragons fly high and mate in midair, usually during a heat wave. Some people believe that the fire-breathing monsters cause the heat wave when they get together above the clouds for their mating season. Earth Dragons mate only during the rainy seasons, when the African and Asian deserts are carpeted with flowers. On these occasions, the males congregate around a female who sets off on her nuptial flight. Although the females are always bigger than the males, they are extremely agile in the air. When a female soars up into the air the males pursue her in a ballet of graceful, aerial acrobatics. The most agile dragon eventually catches up with her. He waits for the moment when the female unfolds her wings to their maximum span and then their union takes place at a great height. He slides under the belly of his beloved and enfolds her in an embrace of wings and talons. Thus entwined, the pair reaches their climax while plunging rapidly down to earth. Only when they are a few meters from the ground do they part and spread their wings to land. After the nuptial flight, the couple withdraw to the heart of the desert, and there the female makes a nest in the warm, damp sand where she lays a single egg, about the size of an ostrich egg, and curiously mottled green and gray. The female abandons the egg, leaving the father to look after it.

He keeps the egg warm to stimulate the hardening of the shell. Meanwhile, the female returns to the place where the other males are waiting for her and the mating ritual begins all over again. The nuptial flight is repeated as many times as is necessary until all the males have an egg. However, from all these unions only one female will be born, for only the dragon's first egg contains a female embryo. As the days go by, the humidity of the sand changes, and the last eggs have little chance of hardening sufficiently to hatch. Thus the law of natural selection prevails and the only dragons who reproduce are the ones who manage to mate with the female during the early flights. When the egg has hardened sufficiently and is ready to hatch, the doting father takes it to a suitable place for the young dragon, usually in the temperate Mediterranean forests, where it will be easy to find food. In general, he places the egg in a hole or in a small cave out of reach of predators, and blocks the entrance leaving only a small opening. The dragon abandons his young the minute he has found a safe place, and he never hunts in the nearby area, so as not to give away the hiding place. However he continues to keep watch over the area, flying backwards and forwards at great height to avoid being seen.