Written by Melanie Smith, Communications Coordinator.
The domestic chicken, is and has long been a ubiquitous global presence. Indeed, one is hard pressed to identify a culture that isn’t familiar with this common bird. Recall, from your youth, the numerous nursery rhymes and fairy tales featuring hens or roosters – Multiply that familiarity across many generations and myriad geographic boundaries, and you begin to gain perspective into the global dominance of this particular avian species.
Gallus gallus domesticus has been the stuff of legend and folklore worldwide going back thousands of years. According to one legend, chickens saved Western civilization in the fifth century B.C. when Athenian troops stopped to watch a cock fight on the road en route to a confrontation with invading Persian forces; the soldiers were apparently heartened by the the tenacity of the battling birds, and thus went on to successfully repel the invaders[1]. The chicken- still a sacred animal in some cultures- has made inspirational contributions to art and religion over the millennia; the watchful hen a symbol of fertility and nurturing, the rooster a universal signifier of vigor and an indicator of good or bad fortune in battle depending on its behavior[1]. Ironically, the associations of chickens in modern American usage include cowardice and panic. This may well be indicative of historical changes in the societal role of this famed poultry.
Male chickens can be fierce creatures, especially when engaged in combat with one another. Roosters have evolved a bony spur on their legs that enable them to inflict significant injuries on rivals during battle. These facts about chickens gave rise to their use as entertainment in cockfights as far back as 5000 BCE[8]. Depictions of roosters engaged in combat have been identified throughout the ancient world, and although now illegal (in the U.S.) and considered inhumane by many, the cockfighting tradition – which involves supplementing the birds battle spurs with blades – still persists in many parts of the world[1].The dominant role of the domestic chicken in todays’ society is obviously food; both their eggs and their flesh have become staples of the human diet. Ancient Egyptians were the first to master egg production – constructing incubation “ovens” heated with straw and camel dung fires[1]. The ancient Romans were the first to create culinary delights including omelets and stuffed chicken, and their farmers recognized the benefits of fattening the birds using food supplements that included wine soaked bread[1]. Archaeologists believe that chickens were first introduced to the Americas by Polynesians in the late 1300’s, but they played a relatively minor role in the American diet until the late 20th century[1]. While the domesticated chicken has long been a familiar site in the barnyard of small family farms, large scale production of eggs and meat lagged behind that of beef and pork. The development that boosted the chicken’s dominance, and enabled it to surpass beef as the most popular meat in America in the 1990s, was the factory farm. Today, more than 50 billion chickens are raised for food annually – the vast majority (74% of meat and 68% of eggs) on factory farms[2]. The average American consumes 80 pounds of chicken per year, exemplifying the profound changes in the relationship between these birds and humanity[1].
So where did this bird that has long infiltrated human culture, filled our bellies, and become an powerful economic force originate? Given their global dominance today, it may be hard to envision a landscape where the chicken doesn’t roam. However, this bird hasn’t always been a common inhabitant of most continents; nor has it always existed in its current form. The domestic chicken, Gallus gallus domesticus, has a complex genealogy going back 7-10 thousand years and involving one or more instance of domestication from one or more wild progenitors[1]. Charles Darwin theorized that (at least some) domestic chickens like arose from red junglefowl, Gallus gallus, native to Southeast Asia, and this assertion has been supported by DNA analysis[1]. Recent investigations indicate that the grey junglefowl also contributed to the domestic chicken’s genealogy, evidenced in part by the yellow skin that both birds share in common[3]. Domestic chickens exhibit both additional similarities to and differences from their wild ancestors (in appearance, behavior, biology, ecology) which merits a comparative discussion.
Red junglefowl prowl the bamboo forests of their limited native range in Southeast Asia, dining on insects, seeds and fruits[7]. They range in size from 18-29 inches in length with wingspans between 15-20 inches[5]. Flight in the species is utilized primarily for escaping ground predators, and for reaching communal overnight roosting areas in trees. Gallus gallus exhibits strong sexual dimorphism[5]. The males possess reddish gold heads and necks adorned with long feathers, topped with fleshy red combs and framed by red wattles[5]. Their chests, underparts and tails are black, they sport green and blue iridescence on their wings and tails along with a white patch on their rumps[5]. The females are comparatively smaller and duller in appearance, their plumage likely evolved as camouflage given that they alone tend to eggs and chicks. During the mating season, males establish monogamous relations with females, attracting their attention using their characteristic “cock-a-doodle-doo” crowing calls and by putting on a displays featuring offerings of food morsels[7]. Following mating, the female will lay between 3 to 7 eggs, incubate these for nearly 3 weeks, and then nurture the precocial chicks for approximately 3 months[5].Like it’s wild ancestors, the domestic chicken is omnivorous, harvesting seeds, insects and even small snakes, lizards and mice if allowed to forage naturally[2]. Gallus gallus domesticus likewise doesn’t frequently take flight, and in fact is less capable in part due to the fact that the most common breeds were selectively bred them to be about twice the size of their progenitors[3]. Chickens also exhibit sexual dimorphism; the males are easily distinguished by their striking plumage, bolder coloration, and the presence of a comb and leg spurs[2]. Domestic chickens have been selectively bred to be fatter and more complacent than junglefowl, and a gene mutation caused them to start laying eggs year round rather than just during a specific breeding season[8].
So what are the implications of Gallus gallus domesticus’ rise to global culinary dominance? For starters, although their popularity has allowed them to conquer the far reaches of the planet, their ubiquity poses a threat to the persistence of wild red junglefowl populations due to hybridization with free-ranging Gallus gallus domesticus along forest edges[7]. Ironically, most domestic chickens don’t enjoy the benefits of a free-range existence in which they are permitted to exhibit their instinctive behaviors. As mentioned previously, most chicken is raised on factory farms – these establishments turn out enormous quantities of chickens and eggs by keeping the birds indoors where they are protected from the elements – in many cases these animals never go outdoors or see the light of day, and they cannot move about or forage freely. Factory farms may rear as many as 20-30 thousand birds, tightly packed in wire cages crowded together in a single building[1]. What’s more, they are fed grain as opposed to their natural omnivorous diets; the primary objective of factory farms is to efficiently convert grain to protein. Their feed is fortified with antibiotics and vitamins both to maximize their growth rates and to prevent the diseases that spread readily and rapidly when so many birds are kept in close, confined and stressful conditions[1].
There are numerous dire consequences that have arisen from our adoption of industrialized poultry production. The antibiotics that are administered so liberally to chickens and other livestock – over 80% of those used in the U.S. annually – have contributed to the recent rise in antibiotic resistance[9]. Most of these drugs are medically important in humans as well, and their rampant use is helping to breed “superbugs” against which these antibiotics are ineffective. The result has been striking increases in human illnesses, medical costs, and deaths; a recent report estimated that by 2050, drug resistant microbes will kill more than 10 million people and cost the global economy $100 trillion[9]!Rearing tens of thousands of birds on small parcels of land also had profound environmental impacts. Industrialized poultry farms produce enormous quantities of manure, and rainwater runoff from these operations flows into streams and rivers, and eventually larger bodies of water, leading to serious surface water pollution. The Chesapeake Bay is a good example of a waterway that has become severely degraded largely due to poultry farm runoff where large scale chicken operations dominate the eastern shore[4].
So what can we do to improve the fate of the worlds favorite poultry? The first step in changing a system that’s not working is to educate oneself. As much as so many of us enjoy eating chicken, do we really want to support the inhumane conditions under which most of them are raised? If so, are we willing to accept the effects of rising superbugs and environmental degradation associated with the practices employed to raise the majority of our poultry around the world? Most people would probably say no, but at the same time would not be willing to quit chicken “cold-turkey”. An alternative approach would be to recognize that a chicken is more than just the sum of its flesh and eggs, and to respect its needs as a living creature. This would involve going back to more traditional poultry farming techniques – where the birds can wander and forage freely. We are seeing a rising trend in people learning to raise poultry in their own back yards. Benefits to this approach include reductions in the amounts of antibiotics and pollution associated with industrialized poultry production. Even if you aren’t able to tend your own flock, you can vote for better practices with your wallet – buy locally raised free range chicken and eggs when possible, or at least voice your concerns and demand that big ag change their tactics. On this note, McDonalds – in response to consumer pressure -recently announced that it will require all of its restaurants to serve antibiotic-free chicken within two years[6]. While we still have a long way to go, improving the reputation of Gallus gallus domesticus will lead to improvements in its quality of life as well as ours. And while I don’t expect that we’ll soon return to worshipping chickens as did the ancients, we may find that their behaviors and personalities are nonetheless fascinating if we take a closer look and consider their wild heritage.
1. Adler, Jerry, and Andrew Lawler. “How the Chicken Conquered the World.”Smithsonian. N.p., June 2012. Web. 17 Mar. 2015.
2. “Chicken.” Wikipedia. Wikimedia Foundation, n.d. Web. 17 Mar. 2015.
3. “Chicken (Gallus Gallus).” A-z Animals. N.p., n.d. Web. 18 Mar. 2015.
4. “Chicken Waste and Water Pollution.” PBS LearningMedia. N.p., n.d. Web. 20 Mar. 2015.
5. Mayntz, Melissa. “Red Junglefowl – Gallus Gallus.” About.com. N.p., n.d. Web. 17 Mar. 2015.
6. McKenna, Maryn. “McDonald’s Chicken Goes Antibiotic-Free. Now What?” National Geographic, 12 Mar. 2015. Web. 19 Mar. 2015.
7. “Red Junglefowl.” Wikipedia. Wikimedia Foundation, n.d. Web. 17 Mar. 2015.
8. Reilly, Lucas. “6 Barnyard Animals and How They Came to Be.” Mental FlossDec. 2014: 48.
9. Rodriguez, Tori. “Essential Oils Might Be the New Antibiotics.” The Atlantic. Atlantic Media Company, 16 Jan. 2015. Web. 20 Mar. 2015.