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
What Bird is That? according to their usual habitat. The accompanying text included brief notes on distribution, breeding and behaviour. While initial sales were poor, history tells us that Cayley had accurately discerned a market need and successfully responded to it. During WWII sales accelerated and Cayley’s first collection, reprinted time and time again, eventually became a household name among birdwatchers and the book was recognised as an Australian classic. The original sponsorship of "What Bird is That?" proved a great investment for the Gould League, who benefited from the sale of its numerous reprints and revised editions. By 1960, it was rated the