Description:
White Bib is a mutation in Coturnix quail that causes the bird to grow white feathers underneath the chin. It has not been well-studied, and rather was suggested in the discussion of a publication studying dotted white (1). It is included here because of the prominence in current lines of EB and Andalusian, as well as listings in several genetic registries (2)(3).
White Bib is suggested to be an autosomal recessive mutation in the study (1), which matches general breeder's descriptions of birds with white bibs appearing in EB lines when the parents do not show any signs of white feathering (4)(6), and lines with the white face breeding true. Birds with a white bib appear to have very consistent phenotype (4) when not selected for, though it can be bred bigger or smaller across the face. Most birds with the proposed white bib have several small sections of white feathers across the chin, and some feathers across the side and top of the beak.
It is possible and has been suggested that this white beard is not a gene at all, but rather a natural expression of white found in EB. The mutation is typically seen on EB (Tibetan and Rosetta), along with Andalusian. It is not commonly found on Pharaoh or other lines. Birds with the white bib commonly are also seen with the white crescent mutation, and often come from lines that have previously had dotted white (1). It is confirmed to not be an expression of dotted white (1)(4).
It is suggested by the author that the mutation may be in a similar linkage group but different locus than other white mutations, and/or EB. This is not confirmed.
More research needs to be done on the mutation to confirm the inheritance and if it is a separate gene or just a different expression of natural EB.
References & Further Reading
Roberts, C. W., Fulton, J. E., & Barnes, C. R. (1978). GENETICS OF WHITE-BREASTED, WHITE AND BROWN COLORS AND DESCRIPTIONS OF FEATHER PATTERNS IN JAPANESE QUAIL. Canadian Journal of Genetics and Cytology, 20(1), 1–8. doi:10.1139/g78-001
Somes Jr, Ralph G. "International registry of poultry genetic stocks." (1988).
Tsudzuki, Masaoki. "Mutations of Japanese quail (Coturnix japonica) and recent advances of molecular genetics for this species." The journal of poultry science 45.3 (2008): 159-179.
Homestead Filkins, (breeder with experience with the white bib) personal communications with the author. 9/7/2024
Carey Blackmon, personal communications with the author. 9/7/2024