From fresh eggs to unique pets, urban chickens capture the imagination of people longing to bring a bit of a rural mystique to their lives. Since many places regulate against keeping roosters within city limits, it is important for prospective chicken keepers to know the sex of their chicks before bringing them home. One solution for the conundrum of sexing very young chickens relies on the principles of avian genetics to produce chicks whose feather color reflects their sex, such as black star chickens. This allows hatcheries and keepers to separate chicks by sex immediately upon hatching.
TL;DR (Too Long; Didn't Read)
Black star chickens are docile, hardy birds produced by crossing a barred hen with a non-barred rooster. Due to the principles of avian genetics, the feather color of the resulting chicks correlates with their sex, allowing keepers to separate chicks by sex very easily. Female black star chicks are solid black.
To understand sex links, it is important to understand a bit about genetics. Among mammals, males carry XY sex chromosomes while females carry XX sex chromosomes. Since each parent donates one chromosome to each offspring, the male parent’s contribution determines the offspring’s genetic sex. For birds, the opposite is true. Male birds carry ZZ sex chromosomes while female birds carry ZW sex chromosomes. In this case, the female parent’s contribution determines the offspring’s genetic sex.
The Z and W chromosomes also carry genes that encode other characteristics, including feather color. This enables breeders to mate chickens of different breeds to select for chicks whose feather colors occur based on their genetic sex. This trait is not heritable, so keepers can not use sex link chickens to produce another generation of sex links.
Black Star Chickens
These chickens, also called black beauty chickens or black sex links, result from mating a barred hen with a non-barred rooster. The barring gene produces chickens with white bars or stripes all over their feathers. Chickens without the barring gene are solid in color. When they hatch, all black sex link chicks emerge covered with black down. However, the male chicks have white dots on their heads and will ultimately grow feathers with white bars like their mother. The female chicks will remain solid black. One common mating that produces black sex links is a Barred Plymouth Rock hen with a Rhode Island Red rooster.
Characteristics of Black Star Chickens
While the ability to tell the sex of the chicks right away is important, it is not the only valuable trait carried by a black sex link hen. These medium-sized birds are excellent layers, producing approximately five brown eggs per week per hen. They also tend to be docile chickens who tolerate winter cold snaps, summer heat waves and the particular stresses of living in confinement better than many other breeds.
About the Author
Melissa Mayer is an eclectic science writer with experience in the fields of molecular biology, proteomics, genomics, microbiology, biobanking and food science. In the niche of science and medical writing, her work includes five years with Thermo Scientific (Accelerating Science blogs), SomaLogic, Mental Floss, the Society for Neuroscience and Healthline. She has also served as interim associate editor for a glossy trade magazine read by pathologists, Clinical Lab Products, and wrote a non-fiction YA book (Coping with Date Rape and Acquaintance Rape). She has two books forthcoming covering the neuroscience of mental health.