Crested chickens

Crested chickens are a group of ornamental chicken breeds characterised by a tuft or crest of upward-pointing feathers on the head.

old engraving of a hen with a crest of feathers
old engraving of a cock with a crest of feathers
Ulisse Aldrovandi, illustrations of crested hen and cock, from the Ornithologiae tomus alter of 1600
Detail of Kippen en eenden by Melchior d'Hondecoeter, circa 1680

History and distribution

A skull excavated in England suggests that crested chickens were present there in Roman times.[1][2] Early depictions of these birds are found in the Ornithologiae tomus alter of Ulisse Aldrovandi of 1600, and in the work of Dutch animalier painters such as Melchior d'Hondecoeter in the later seventeenth century. After the exhibition poultry breeding developed in Europe and North-America in the nineteenth century, several old crested breeds became widely known. Original crested chickens originate from the Netherlands, France, Italy, Poland, Russia, and in the Western Balkans. Apart from these breeds, crested chicken are found in Africa and Iceland.

Genetics

The development of the feather crest is based on the mutation "Crest" (Cr). Its inheritance is incomplete autosomal dominant. This means, that homozygous but also heterozygous animals show a crest, which is however more pronounced in homozygotes.[2]

Skull form of a crested chicken (B) and of a bankiva (A)

Vaulted skull

The extreme upright stand of the head feathers of many breeds, like the Polish, can be attributed to a skull malformation, which is known as cerebral hernia or vaulted skull. Neurobiological investigations showed that this malformation alters the brain anatomy without any functional relevance.[3]

List of crested chicken breeds
Dutch crested chicken or Polish

References
  1. Don Brothwell (1979). Roman evidence of a crested form of domestic fowl, as indicated by a skull showing associated cerebral hernia. Journal of Archaeological Science 6 (3, September 1979): 291–293. (subscription required).
  2. Yanqiang Wang, Yu Gao, Freyja Imsland, Xiaorong Gu, Chungang Feng, Ranran Liu, Chi Song, Michèle Tixier-Boichard, David Gourichon, Qingyuan Li, Kuanwei Chen, Huifang Li, Leif Andersson, Xiaoxiang Hu, Ning Li (2012). The Crest Phenotype in Chicken Is Associated with Ectopic Expression of HOXC8 in Cranial Skin. PLOS ONE. 7 (4): e34012. doi:10.1371/journal.pone.0034012.
  3. Heiko D. Frahm, Gerd Rehkämper (1998). Allometric Comparison of the Brain and Brain Structures in the White Crested Polish Chicken with Uncrested Domestic Chicken Breeds. Brain, Behavior and Evolution. 52 (6): 292–307. doi:10.1159/000006574. (subscription required).
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