How the Chicken Dominated the American Diet
Reading Mark Bittman’s fascinating book Animal, Vegetable, Junk the other day, I happened across this disturbing fact: 3/4 of the Earth’s bird biomass is chickens on farms. That’s right: if you weighed all of the birds on this planet, 75% of the weight would come from chickens. We eat nine billion chickens a year in this country. That’s 74 chickens for every pig killed last year for food, and 231 for every cow that became beef. Chicken flesh is everywhere in American cooking — sometimes as a prized ingredient, but often as bland filler.
The chicken has come to occupy a role unlike any other species within our industrial agricultural system. The proliferation of the chicken and the food system that boosted it are both quite recent developments, as it turns out. So, why does the chicken play such a key role in our food system, when did this start, and how have humans changed chickens themselves?
Why do we eat chickens?
There are a lot of birds out there that humans could be eating — ducks, geese, emus, robins. But almost all the poultry consumed by humans comes from one species: gallus gallus domesticus, the chicken. Why did this bird, out of more than 10,000 bird species, became a staple of human food?
The chicken seems to have originated as a jungle bird in southern Asia; the ancient Mesopotamians referred to it as the bird from the Indus Valley. Chickens were an attractive candidate for domestication because of their relative flightlessness. They had evolved to browse along the jungle floor, using their wings only occasionally, to flutter up to a branch and evade a predator. Unlike many birds, they don’t really travel far from their birthplace in their lifetime. In short, chickens were easy to catch and control. Humans figured this out and had domesticated them by 8,000 BCE.
Even though chickens were domesticated fairly early in history, they weren’t a dominant food source for the civilizations that raised them. Before the modern era, chickens were raised mostly for their eggs (a much more sustainable…