The two chicks are an accident of recessive genes. Their eggs were the result of the mating of a hen and a rooster from another very rare, closely-related, almost-extinct breed–Black Java chickens.

Two weeks ago, there were only 300 known auburn Java chickens in the world, which means something if you’re a chicken expert. Make that 302. A pair of auburn Java chicks hatched at the Kohl Children’s ...