This variety of Marans is not the most rarest that exists in the breed as it regularly appears as a result of Brown-Red and Silver-cuckoo crosses. Although rare, this variety is no in any risk of disappearing. We can define the Birchen (Silver-Black) Marans as a Brown-Red that has its copper/red plumage replaced by silver-white to give a Birchen pattern, ER. The silver (S) color factor, which is dominant to the gold (s+) allele, is present in the genotype of the Silver-Cuckoo variety. From this, we can understand the relative frequency of the silver (S) genes in the breed. So in the absence of the cuckoo allele, the Marans breeding stock, which carry (S) silver, give rise to Birchen birds from Brown-Red X Silver Cuckoo. Care must be taken to remove the red enhancers, Mahogany and Autosomal Red; otherwise this could result in a showing of red, especially on the shoulders of the cock. The Birchen Marans leaves nothing to be desired, when compared to the famous Brown-red variety as far as aesthetic qualities are concerned. The plumage colr is a very spectacular Silver & Black combination.  Today we find some very correct Birchen stocks that present to a good standard and lay especially nice extra dark reddish-brown eggs.