I read it sometime in the early 70's. All I remember is that a girl is in science class and the teacher is talking about how certain breeds of chickens are gone because they've been cross-bred out of existence. The next day, a male student brings in cages filled with the birds that the teacher said were extinct. The girl is impressed by the boy and asks to see more.
Dave’s Song by Robert McKay?
YES! I thought it was Canary Red, same author, but it was not. THANK YOU.