It is most likely the case that the grey jungle fowl was crossed with an early form of the domesticated chicken.
From the sciencedaily.com
Wild boar, orangutans, parakeets, jungle fowl, partridges, and other animals congregate to stuff themselves.
From the sciencedaily.com
The chicken was probably domesticated for its eggs from jungle fowl native to tropical and subtropical Southeast Asia and India before 7500 BCE.
From the en.wikipedia.org
Having seen its wild ancestors, the Burmese fowl, also called the northern red jungle fowl, all over India and Bali, I can confirm that these birds fly, and quite well.
From the theatlantic.com
Swedish and American scientists identified roughly 7.5 million genetic variations between domesticated chickens and the jungle fowl, their primary wild ancestor.
From the thenewstribune.com
The grey and red jungle fowl have, at present, disjunct ranges, but that may be a product of recent ecological changes, including human alterations of habitats.
From the scienceblogs.com
They studied how individual patterns of gene activity in the brain were different for modern laying chickens than the original form of the species, the red jungle fowl.
From the sciencedaily.com
In the central plains they leap from sugar cane bearing cheese and Guava paste while in the eastern Sierra Maestra mountain range they jump out of the jungle holding up fruits and fowl.