Extended Brown

EB is the mutation that causes both Rosetta (one copy of the gene) and Tibetan (two copies of the gene). It is often called "brown" in early scientific papers, but is not to be confused with actual wildtype (sometimes called jumbo brown) or sex-linked brown.

The EB gene increases the eumelanin pigment in the bird's body, the same pigment that makes human hair and eyes brown. It does the same for quail--in both Rosetta and Tibetan, it will make the entire bird a dark brown color, including the eyes, beak, and skin on the feet. Each feather will have slight black horizontal barring, giving the bird an even darker look. There is a wide range of natural color for Tibetan and Rosetta, from a reddish brown to a deep chocolate, but in almost all cases, the darker brown is preferred.

EB is often considered to be a base pattern because it affects so much of the bird's pattern. It can be crossed with Fawn to yield Fawn-Enhancement, which creates a yellow horizonal barring pattern on each feather.

Rosetta:

In Rosetta (heterozygous EB), the bird will be almost entirely reddish brown, but will have light yellow shafts going

vertically up each feather (1). They will tend to be a slightly lighter color than Tibetan, and more of the facial markings may be present. Toes will usually be a mottled pink and brown, with more pink than on a Tibetan bird.

These will not breed true, as they have one copy of EB (heterozygous).

Rosetta x Rosetta will get you 25% Pharaoh, 25% Tibetan, and 50% Rosetta.

Rosetta x Pharaoh will get you 50% Rosetta, 50% Pharaoh.

Rosetta (one copy of EB)--notice the yellow shafting in each feather. Bird and photo from Martin Yardley

Tibetan

In Tibetan, the entire bird will be a dark brown, and the shaft of each feather will be brown instead of yellow. They can be a very dark, almost black color, but are not to be confused with Recessive Black or TOF Blacks. Feet will be a dark brown, with some pink toes possible, but all brown is preferred. Facial markings will still be present but often hard to see.

Tibetan (two copies of EB) -- notice the black center to each feather. Bird and photo from Martin Yardley

These will breed true.

Tibetan x Tibetan will give you 100% Tibetan offspring.

Tibetan x Pharaoh will give you 100% Rosetta offspring.

Tibetan x Rosetta will give you 50% Rosetta and 50% Tibetan offspring.

For more information about breeding with this kind of gene, including tips and tricks and a full explanation of how these results were calculated, please see here.