Birchen

Birchen, allele symbol E^R, abbreviated as E^R or ER, is the second most dominant of the e-locus alleles, only recessive to Extended Black . The birchen color name is applied to game birds with a silver groundcolor. Gold or red variants were called red-brown.

Phenotypic effect

Birchen is a very neat black enhanced chicken color. Typical is the lacing of the upper breast feathers of both genders with a groundcolored rim. This can however easily be covered/removed by additional genes. In silver Sussex this lacing can be extended to most of the body.

chick down

Often the chick down is solid black or dark brown, dark shanks.

rooster

A black enhanced form of the black breasted (wildtype) phenotype, with one significant difference: the wing triangle is black instead of groundcolored (pheomelanin). This is called "crow wing". Hackle, shoulder and saddle are groundcolored with like the wildtype rooster.

hen

Solid black with a nicely patterned groundcolored hackle and breast lacing.

Heterozygosity

• Birchen is completely dominant to wheaten .
• Extended black and birchen are very similar, so heterozygotes probably not obvious. Breast lacing probably absent.
• e+/e^b: heterozygote hens often show partridge like stippling on some areas but are generally heavily melanized.

Epistatics

Birchen is epistatic to (covers) columbian.

Like with Extended Black, when diluted to blue, the phenotype can be affected by pattern genes like Pg and/or Ml to render a black lacing. Other patterns like black multiple lacing or spangling on a blue background can not be achieved.

Birchen is not epistatic to Db and the presence of this gene enables columbian-like restricted patterns on a birchen base.

Patterns

Birchen is a very suitable base for creating contrasting patterns like:

• Autosomal barring eg Campine, Fayoumi.
• Spangled eg Hamburgh.
• Single Laced eg Sebright, Polish.

Birchen is thought to enable patterning of the tail area when in conjunction with Db.

Solid black

Birchen is often used as a base for creating a fully black chicken. Compared to Extended Black the shank color is less dark, possibly allowing yellow legs more easily.