By Jan TenBruggencate
Kauaʻi’s famous chickens are, of course, not standard domestic fowl.
They’re a blend that differs depending on where you are, of ancient Red Jungle Fowl, of bred fighting chickens and of domestic meat-and-eggs stock.
The Red Jungle Fowl are among the animals carried by early Polynesian voyagers throughout the Pacific. They are the descendants of wild jungle fowl collected in the forests of Southeast Asia.
Other early travelers carried similar birds westward to Europe and eventually to the Americas, all the while selecting for specific traits, like frequent egg-laying, good size and interesting coloration.
A team of researchers in 2015 published a report on the genetics of the island’s feral chickens, and confirmed both the Polynesian ancestry and the invasion of genetic material from domestic chickens. That said, they are still all chickens, and their scientific name is Gallus gallus.
“Our data support the hypotheses that Kauai’s feral G. gallus descend from recent invasion(s) of domestic chickens into an ancient Red Junglefowl reservoir,” wrote Eben Gering and his co-authors. Gering is with the Kellogg Biological Station at Michigan State University. Their paper is “Mixed ancestry and admixture in Kauai’s feral chickens: invasion of domestic genes into ancient Red Junglefowl reservoirs.”
Some folks have suggested that the Polynesian-introduced Red Jungle Fowl had disappeared from the Islands, and were entirely replaced by escaped domestic birds. But that is not the case.
Rather, they have interbred, and the results are apparent. Red Jungle Fowl had a classic look: the males had a showy red, black and green feather pattern and the females were a mottled brown much like pheasant and francolin hens.
The interbreeding has changed that “with the classic red, black and green feather pattern of the RJF giving way to far more variable coloration in domestic and fancy chicken breeds,” the biologists said.
The crows of the roosters are also different between domestic and jungle fowl, as is skin color.
Generally, the more wild Red Jungle Fowl lineage a chicken contains, the less useful it is for domestic use: they tend to lay smaller eggs, lay them infrequently and they tend to be smaller than a lot of domestic breeds.
As the paper suggests, Red Jungle Fowl are “poorly suited to commercial food production.” On the other hand, they are endangered in their native habitat, and are worthy of conservation.
Kauaʻi residents recall that the feral chicken population seemed to boom after Hurricane ʻIwa in 1982 and again after Hurricane ʻIniki in 1992. High winds destroyed a lot of domestic chicken coops and allowed those birds into the wild where they reproduced, often with Red Jungle Fowl.
The study confirmed that: “Increased densities of feral G. gallus coincided with two major storm events … that damaged island infrastructure and may have facilitated the feralization of escaped livestock.”
Genetic analysis of Kauaʻi chickens suggests that at least some of their genetic material comes from birds that have been in the Islands for nearly 1,000 years. That supports their Polynesian migration association.
- Jan TenBruggencate is a Kaua‘i based writer and communications consultant.