Rookery
Rookery - A protected area where gargoyle clans store their eggs until they hatch. The rookery of the Wyvern Clan was a cave below Castle Wyvern with at least one entrance that leads into the Castle's courtyard.
Rookery Generations
Gargoyle eggs hatch in the rookery every 20 years (those years ending in 18, 38, 58, 78 and 98). Each rookery generation is raised together by the Clan. The closest biological relation between two gargoyles in a rookery generation is first cousins. Although none of the gargoyles are biological siblings, they view each other as rookery brothers and sisters. For instance, Goliath, Demona, Othello, Desdemona, Iago, and Hyppolyta are rookery siblings, though none of them are closely related. Similiarly, all of these gargoyles look at Hudson as their rookery father because he fathered an egg in their rookery generation. Angela, Gabriel, Ophelia and the rest of the Avalon Clan look at Goliath, Demona, Othello and Desdemona as their rookery parents. Gargoyles tend to choose mates from among their rookery brothers or sisters, though this is not always the case (See Broadway and Angela or Yama and Sora).
Apocrypha
Some have theorized that the gargoyle urge and need to have a protectorate of some sort evolved from the long-term, vigilant protection of a clan's rookery, and the surrounding area, and thus the next generation.