Silkie (烏骨雞), meaning 'black-boned chicken'. Melanism which extends beyond the skin into an animal's connective tissue is a rare trait, and in chickens it is caused by fibromelanosis, which is a rare mutation believed to have begun in Asia. The Silkie and several other breeds descended from Asian stock possess the mutation. Disregarding color, the breed does not generally produce as much as the more common meat breeds of chicken. Silkies lay a fair number of eggs, of a cream color, but production is often interrupted due to their extreme tendency to go broody; a hen will produce 100 eggs in
Bird-of-paradise lek-type mating system. Others, such as the "Cicinnurus" and "Parotia" species, have highly ritualised mating dances. Males are polygamous in the sexually dimorphic species, but monogamous in at least some of the monomorphic species. Hybridisation is frequent in these birds, suggesting the polygamous species of bird of paradise are very closely related despite being in different genera. Many hybrids have been described as new species, and doubt remains regarding whether some forms, such as Rothschild's lobe-billed bird of paradise, are valid. Birds-of-paradise build their nests from soft materials, such as leaves, ferns, and vine tendrils, typically placed in a tree