Question:
Can my black Ameraucana carry the blue gene and blue Ameraucana pop up later in my black Ameraucana pen?
Answer:
No. If a black Ameraucana has the blue gene, you will see it in the plumage color of the bird. The blue gene is always expressed in the phenotype of black Ameraucana if the bird carries it.
The blue gene (Bl) is a diluting gene. It is known as an autosomal incomplete dominant gene.
In its heterozygous form (one copy of the Bl gene), black feathers are diluted to create blue plumage. In its homozygous form (two copies of the Bl gene), black feathers are diluted to create splash plumage. The non-mutated version is black.