The domestic turkey (Meleagris gallopavo) and the domestic chicken (Gallus gallus domesticus) are common poultry species found globally. Both birds belong to the same order, Galliformes, but they are classified into different genera. This classification leads many to wonder if they can successfully interbreed and produce offspring. Examining the science behind their reproductive compatibility reveals clear biological boundaries between these two distinct species.
The Biological Verdict on Interspecies Mating
The definitive answer is that turkeys and chickens cannot produce viable, fertile hybrid offspring. Physical mating attempts between a turkey and a chicken may occasionally occur due to behavioral similarities or shared environments. However, these interactions are a display of non-specific mating behavior and do not result in a lasting biological outcome.
If fertilization is attempted, either naturally or through controlled artificial insemination, the resulting egg is almost always infertile and fails to develop. The reproductive barrier between the two species is robust, preventing the formation of a viable embryo. Extremely rare instances of a fertilized egg beginning development have occurred in controlled laboratory settings, but the resulting embryos are non-viable and die early in incubation.
Genetic Barriers and Chromosomal Differences
The scientific reason for this incompatibility lies within the nucleus of their cells, specifically in their chromosomes. The domestic chicken has 78 chromosomes (\(2n=78\)), while the domestic turkey possesses 80 chromosomes (\(2n=80\)). This numerical mismatch alone presents a significant hurdle for successful crossbreeding.
During the formation of gametes (sperm and egg), chromosomes must divide precisely so that each sex cell receives a complete set of genetic material. When a chicken gamete (39 chromosomes) and a turkey gamete (40 chromosomes) attempt to fuse, the resulting zygote has an abnormal number of 79 chromosomes. This odd number prevents the chromosomes from pairing correctly during subsequent cell divisions, a process called meiosis.
Beyond the difference in total number, the structure of the chromosomes is also incompatible. Genetic studies show that certain chicken chromosomes correspond to two separate turkey chromosomes, indicating structural rearrangements over evolutionary time. This difference in both number and organization prevents the hybrid embryo from receiving a functional, balanced set of instructions. This genetic isolation leads to early developmental failure and death, effectively maintaining the integrity of each species.
Observed Outcomes of Attempted Crossbreeding
In the few documented cases where scientists successfully used artificial insemination to force fertilization, the resulting offspring were rare and severely compromised. These hybrids, sometimes called “churks,” were often sickly, with physical deformities such as crooked limbs and beaks. Furthermore, the few that survived beyond the embryonic stage were exclusively male and sterile.
A common point of confusion is the “Turken,” or Naked Neck Chicken, which many mistakenly believe is a chicken-turkey hybrid. The Turken is actually a distinct breed of chicken (Gallus gallus domesticus) that carries a dominant gene for reduced feathering on its neck. Its appearance resembles that of a turkey, leading to the folklore that it is a crossbreed, but it is genetically all chicken.