I removed her from the nest and the golf ball she was setting on a couple of times, to loud squawking. And she promptly returned. In some sense, it was a good test. I knew she was serious about setting.
As we talked, we got the idea of putting some eggs under them. He located a farmer who had fertile hatching eggs for sale, and soon both our hens were setting on real eggs. She's got six eggs under her, three Coronation Sussex and three Welsummer. No problem telling them apart -- the Welsummer eggs are dark brown, with speckles. Beautiful.
Coronation Sussex are an unrecognized very rare variety. I've never seen one. The plumage pattern is similar to a Delaware, but instead of black the contrasting feathers are silver or lilac. The friend who picked up the eggs, told me the birds he saw were beautiful.
This hen is a Speckled Sussex. Other good broody breeds include Ameraucana, Asil, Barnevelder, Brahma, Buckeye, Chantecler, Cochin, Cornish, Cubalaya, Delaware, Dominique, Dorking, Dutch, Faverolle, Holland, Japanese, Java, Jersey Giant, Kraienkoppe, Marans, Nankins, New Hampshire, Old English Games, Orloff, Orpington, Polish, Plymouth Rock, Rhode Island Red, Silkies, Sussex, Welsummer, Wyandotte.
All games are usually good brooders. Madagascar Games, Malgache, are reported to be willing to adopt chicks from other broods and of different ages. Males sometimes brood chicks.
They vary by individuals and some lines are better brooders than others. Ask the breeder how broody his birds are.