Zebra finch mutations can occur on different types of chromosomes the first type of chromosome is involved in determining if a bird will be male or female. these chromosomes are called sex chromosomes and a mutation occurring on them is considered sex-linked since it will be passed on differently to the males and females. In zebra finch the male has matching sex chromosomes abbreviated as ZZ and females have mismatched chromosomes abbreviated as ZW (in humans the sex chromosome arrangement is different, the females have matched sex chromosomes XX and the males have mismatched sex chromosomes XY). The second type of chromosome is called autosomal and refers to all chromosomes except the sex chromosomes.
Mutations can also be dominant meaning that they always appear in any bird with the dominant trait and it will hide other mutations. The mutations that are hidden by the dominant trait are called recessive. Some mutations show intermediate degrees of dominant and recessive which may depend on a mixture of mutations in each individual bird.