The story
The Ayam Cemani chicken is one of the most colorful birds in the earth. The bird’s feathers, beak, comb, tongue, and toes, as well as its bones, are all a stunning blueish black. The chicken meat seems to have been marinated in squid ink as well.
Scientists call it skin hyperpigmentation, and the cemani, which lives in Indonesia, is the most extreme case of it. Another breed is called a silkie because its feathers are soft and look like hair, and the black H’Mong chickens of Vietnam and the smartphone of Sweden all have hyperpigmented skin and organs. Scientists call the condition fibromatosis.
Leif Andersson, a biologist who specializes in domestic animal genetics at Uppsala University in Sweden, claims that “we have evidence that it is a complex rearrangement in the genome.”
Andersson says that all of these chickens can trace their change back to a single bird that may have lived hundreds or even thousands of years ago.
“The mutation that causes fibromelanosis is very strange, so we know it only happened once,” says Andersson.
While many various species of animals, including black panthers, servals, a melanistic flamingo, black-scaled geckos, and snakes, have been found online to display melanism, the chickens Andersson examines take this coloring to a whole new level.
how it works
Endothelin 3, or EDN3, is a gene found in the majority of vertebrates that, among other things, governs skin color. And during the development of a normal chicken, certain cells, such as those in the epidermis and feather follicles, express EDN3, which initiates the migration of melanoblasts, or the cells that go on to produce pigment.
In the hyperpigmented chickens, however, virtually all of the body’s cells express EDN3, producing up to ten times as many melanoblasts and resulting in tar-like bones and organs.
“It’s a mis-migration,” says Andersson. “Pigment cells migrate to the incorrect location if excessive endothelin 3 is expressed in the incorrect locations.”
The birds’ health doesn’t seem to be hurt by the change, which is good news.
In fact, the reverse is true. The dark color of these types has made them more valuable in the eyes of breeders and gourmets, who say the meat and bones have a unique and rich taste.
Even though experts now know what makes these chicken types unique, they still don’t know much about their past.
History
Many people believe that Marco Polo’s brief writings are the earliest recorded mention of black-boned hens. While on a journey to Asia in 1298, the traveler described a particular kind of chicken that “have hair like cats, are black, and lay the best of eggs.” Nobody is certain, but based on what you mentioned, it seems to be a Silkie.
Andersson says that from there, the trait probably spread around the world by cattle owners who liked how unusual the birds’ colors were. There’s even a story about a traveler who brought back a black chicken from a trade route in East Asia, which could explain how the Svarthona got to Europe.
“I think it’s pretty clear that people like variety among their domesticated animals,” says Andersson, who has also studied where the silkie’s feathers come from genetically and is now looking into how chickens get their crests.
Even though the breeds have been around for hundreds of years, the animals themselves are still pretty rare.
