by John Fowler
ADA Bulletin (Sep-Oct 2002)
A question was raised after the President's Message in the May/June DoveLine as to how an albino cock mated to a white hen could produce wild type offspring. So maybe there is some value to reviewing the albino mutation and what it does.
The albino mutation was first discovered in Japan. Drs. Hollander and Miller at Iowa State University imported this color to the U.S. in 1967. Dr. Miller's "J" strain of birds became the source of all albino ringnecks in the U.S. (Miller, 1984)
The albino mutation prevents the production of melanin. Melanin is the color pigment for the feathers and since no melanin is produced this bird has a pure white-feathered body, tail and head. There is no neck ring and no undertail bar color. The eyes are bright pink. Eye color is caused by melanin and its reflection and absorption of light. More melanin absorbs more light giving a darker eye color. The eye color of the normal wild type is deep red with a tiny greenish ring. The normal white is best thought of as a dilution of the wild type and has orange eyes. Less melanin absorbs less light and we see a lighter color. Albino is, by definition, the absence of melanin. The bright pink eye is caused by light striking the blood vessels in the eye and reflecting back. Some albinos develop a creamy iris somewhat hiding the pink eye effect.
Albino is a regular autosomal recessive gene and the genetic symbol is al. Albino can only be expressed in the homozygous condition -- an albino offspring must receive one copy of the gene from each parent. The albino gene works to block the production of melanin. The coloring material in the feathers and eye pigments of doves and pigeons is melanin. Since no melanin is produced the feathers are always white and the eyes are bright pink. Because no melanin is produced, albino is epistatic to (or hides) all other color mutations in the ringneck dove.
Albino Cock X Albino Hen = 100% Albino offspring
Albino Cock X Wild Type Hen = 100% Split (Wild/Albino) visual wild
Wild/Albino Cock X Wild/Albino Hen = 25%
=50% Split (Wild/Albino) visual wild
Albino Cock X Wild/Albino Hen = 50%
= 50% Split (Wild/Albino) visual wild
An albino ringneck could be wild type at the sex-linked locus as in the case of George Schutt's albino cock. An albino ringneck could genetically be any of the known colors and yet it will appear visually as an albino. When this albino is paired with any of the known colors it will produce offspring according to its genotype and the genotype of its mate. I have an albino hen that is white at the sex-linked locus and carries tangerine. Were she not homozygous at the albino locus she would be a visual pink. When paired with a dark frosty cock carrying albino the offspring have been ash, dark frosty, tangerine, dark and albino.
How can you tell the difference between a true albino and the normal white? The normal white is often mistaken for albino until about three weeks of age. However, there are some early characteristics that make it possible to distinguish between the two. The albino hatchling will have extremely sparse down -- almost naked -- at hatching, while the down of the normal white hatchling is white and sparse. Both will have pink eyeballs, but the eye of the albino will not change color. The eye of the normal white is pinkish until about three weeks of age when the pink eye begins to take on a gray hue. The albino will keep the bright pink eyes after three weeks of age. Also, in the older white there is the presence of a light tan undertail bar. The white rosy will have a more extreme dilute bar and the bulleyed white will have the faint bar often on only the two outer tail feathers only, but sometimes other tail feathers will show the faint bar.
Because of the lack of pigment in the eye, the albino cannot see as well as normal birds. Young squabs are less able to find food and water and may need assistance in finding the food and water cups. Also, the albino may have problems seeing in bright sunlight and if kept outdoors are more likely to develop eye problems than normal birds. However, with lowered light levels albinos seem to have few problems. They could easily make great indoor pets.
Miller, Wilmer J. 1984 Genetics Of The Ringneck Dove, Streptopelia risoria. II. Description of mutants Albino, an autosomal recessive. Gene symbol = al. ADAN Sep/Oct '84: 3-5