Birds
Red Junglefowl
Gallus gallus · also called wild chicken
There are more chickens on Earth than any other bird, by a wide margin. Every one of them descends from a shy, fast, tree-roosting pheasant of the Southeast Asian forest: the red junglefowl.
Overview
Gallus gallus lives in forest edges, bamboo, and scrub across South and Southeast Asia. It is a wary, strong-flying forest pheasant that scratches the leaf litter for seeds, fruit, and insects and roosts high in trees at night.
The chicken’s wild ancestor
The domestic chicken was bred from the red junglefowl in Asia over the last few thousand years, with the grey junglefowl adding the yellow-skin gene. The wild bird still gives a shorter, higher cock-a-doodle-doo, moults into a drab eclipse plumage for half the year, and lays a single small clutch — all things breeding has removed from farm chickens.
Wild versus farmed
There are roughly 25 to 35 billion domestic chickens alive at any moment; wild junglefowl number in the millions and are falling.
Status
Least Concern as a species, but the wild gene pool is being diluted by interbreeding with feral and village chickens, so genetically pure wild junglefowl are becoming rare.
Red Junglefowl: common questions
Is the red junglefowl really the ancestor of the chicken?
Yes, it is the primary wild ancestor. Domestic chickens were derived from the red junglefowl through domestication in Asia, most strongly supported by genetic evidence pointing to Southeast Asia and to a period within roughly the last 3,500 years, though people kept junglefowl in captivity earlier than that. The grey junglefowl, a separate species of the Indian peninsula, also contributed some genes, notably the gene for yellow skin and shanks that many chicken breeds have. So the chicken is essentially a heavily modified red junglefowl with a dash of grey junglefowl.
How different is a wild junglefowl from a farm chicken?
Very different in behaviour and biology, despite being the same species. A red junglefowl is a wary, athletic forest bird that runs and flies well, roosts in trees, keeps to a small flock, lays a single small clutch a year, and moults into camouflaged plumage for half the year. Domestic chickens have been bred over millennia for tameness, fast growth, large body size, and, in laying breeds, for producing an egg almost every day for months, which no wild bird does. A junglefowl also weighs only about 0.5 to 1 kilogram, far less than a meat chicken. Put simply, the wild bird is built to survive in a jungle and the farm bird is built to be farmed.
How many chickens are there compared with wild junglefowl?
The contrast is staggering. There are around 25 to 35 billion domestic chickens alive at any given time, making the chicken by far the most numerous bird on the planet and one of the most numerous vertebrates of any kind, and something like 70 billion are raised and slaughtered each year. Wild red junglefowl number in the millions at most and are declining. The chicken is one of the clearest examples of how domestication can turn a modest wild animal into one of the most abundant creatures on Earth, with its bones now a marker of the human age in the fossil record.
Why does hybridising with domestic chickens threaten the wild bird?
Because it erodes what makes the wild junglefowl wild. Where free-ranging village chickens and feral chickens overlap with wild junglefowl, the two interbreed readily, and domestic genes for things like continuous breeding, loss of the eclipse moult, tameness, and larger size flow into the wild population. Over generations this can leave a population that looks and behaves less like a true junglefowl and more like a feral chicken, and it means the original wild genetic resource, valuable for understanding poultry and for future breeding, is being lost. Some studies suggest genuinely pure wild red junglefowl are now rare across much of the range.