For Eben Gering and his colleagues at Michigan State University, it matters not why the chicken crossed the ocean, but rather what happened when it got to the other side.
Gering, a postdoctoral research associate in zoology, led a team of scientists examining the ancestry of Kauai’s feral chicken population. The results, published in the March 6 edition of the journal Molecular Ecology, focuses on likely interbreeding between the red jungle fowl believed to have been brought to the islands by ancient Polynesians and chicken breeds developed more recently in Europe and raised worldwide.
The scientists said their research, part of a subfield of zoology known as invasion genetics, could help to mitigate damage caused by invasive species in the future and possibly enhance the genetic traits of domestic chicken breeds.
"It is crucial that we identify and conserve the genetic variation that still remains in the red junglefowl," Gering said in a statement released by the university. "This variation could soon be essential for the improvement or evolutionary rescue of commercial chicken breeds."
Gering and his team found that some feral chickens were a perfect genetic match for chickens that existed in Hawaii before Capt. James Cook’s arrival in 1778. Other chickens matched the genetic profile of domestic birds developed for commercial consumption.
Red jungle fowl, while hale and hardy, are not considered commercially viable.
Many of the birds examined showed traits from both types of chicken, a result of likely interbreeding made possible by the escape of domesticated birds into the wilderness.
The scientists said that damage caused by Hurricane Iwa and Hurricane Iniki led to the release of many domestic chickens.
The study examined the appearance, behavior and vocalizations of feral chickens in comparison with their likely ancestors.
As the team concluded, Kauai’s feral chickens "now present something of a conundrum, as they exhibit genetic and phenotypic signatures of (red junglefowl) ancestry, reflecting possible ‘heritage’ origins, as well as traits and alleles (an alternative form of a gene that arises from mutation) from invasive domesticated breeds. This complexity presents many challenges and possibilities for further evolutionary studies of ‘reverse-domestication’ processes."
Such research could one day help to improve the condition of commercially raised chickens, which are prone to rapidly developing pathogens and fertility problems linked to inbreeding.
"Darwin drew heavily from his studies of domesticated species to develop his theory of evolution," Gering said. "This can provide important insights into evolution in action within human altered landscapes, and may even someday help build a better chicken."
