Chicken dinner...

Usually it's the chicken being eaten...

Chickens are the most abundant bird on Earth. Obviously this number would fluctuate any time dinner was being prepared, but in 2010, the United Nations Food and Agriculture Organization estimates there were 19.4 billion chickens on the planet. Thanks to the ease of production, the taste of fried chicken, and the flexibility of any-way-you-like-it eggs, there are more chickens than any other type of bird.

Grilled chicken is served at the bus stop in between Kampala and
Jinja in Uganda. One skewer? 1000 Ugandan shillings, about $.40 USD.

The totally enormous, wild flocks of red-billed queleas in Africa, which have never been accurately quantified, may hold as many as 10 billion individuals*. What about some of the other species that have expanded worldwide, also due to human influence? Feral rock pigeons? A mere 260 million worldwide. Common (European) starlings? Just 310 million. House sparrows? 540 million. Even among the next biggest group of farmyard birds, domestic ducks number only about 1.2 billion (and this group is comprised of two species). We humans love our chickens.

Chickens are sexually dimorphic. Size, coloration, head details, and
feather type distinguish the male from female.

The chicken is in the bird family Phasianidae, which includes grouse, pheasants, partridges, and turkeys. The wild ancestors of chickens, Red Junglefowl (Gallus gallus), still exist today and inhabit subtropical and tropical forests in the lowlands and low-altitude mountains of Southeast Asia (**). They were domesticated by humans around 8000 years ago in China and India (***).

Not a chicken!
This Hildebrandt's Francolin (Francolinus hildebrandti) is another member
of the family Phasianidae and is found in Eastern and Central African
highland savannas.  The francolins and spurfowl of Africa are also hunted
for food, though not domesticated, and sometimes kept as pets.
Picture from Ngorongoro Conservation Area, Tanzania

Apparently, one of human’s earliest uses of the chicken was for cockfighting. Over our history, humans have raised chickens for their feathers (like the recent feathered hair fad, special fishing lures), their protein (meat and eggs), their waste (as fertilizer, which is a useful byproduct), as experimental subjects, and for entertainment (fighting, poultry exhibitions). Whatever your opinions are on the use of animals for human benefits, domestication of the chicken has become an important feather in human’s proverbial cap.

Eggs provide an important protein source for the students at Rwanda's
Agahozo-Shalom Youth Village, where they produce their own as part
of their sustainability plan.

Of all the products we get from chickens, meat and eggs are the most important. They are cheap, easy to raise, and provide a mouthful of nutrients that our bodies need. For example, assuming a 2,000 Calorie diet, one half chicken breast with skin and bone removed (86 grams) contains more than 20% of a person’s daily values of protein, vitamin B3 (niacin), vitamin B6, phosphorus, and selenium, plus other nutrients in smaller quantities. That amount of chicken breast with the skin removed contains just 5% of one’s daily value of fat and 24% of cholesterol. About the same quantity of eggs (88 grams: two medium-sized eggs or one large and one small), contain more than 20% of your daily value of protein, riboflavin, and selenium, plus vitamin B12 (19%) and phosphorus (17%) with just 14% of your daily fat. On the downside, that amount of eggs contains 124% of your daily cholesterol. 

A hen with her chicks in Ecuador.

For those of you wondering, chickens are not on my life list of birds. Domesticated birds or wild birds captured as pets (or in zoos for that matter) do not count. Seeing a chicken is becoming easier, however, as several municipalities, including Columbia, MO, have changed their laws in recent years to allow the keeping of hens in backyards or community gardens. New York City, San Francisco, and Los Angeles, among many others, allow residents to have a limited amount of chickens in their yards, too.

Although chickens originated in the forests of Asia, they are now a global bird. The only remaining question is, “why did the chicken cross the road?”

To escape the cleaver-wielding human, of course.

Footnotes

*The "up to ten billion" number of Red-billed Queleas pops up on various sites, including the Wikipedia entry. I followed Wikipedia's citation to a trail guide site (http://www.trails.com/arts/amazing-bird-records.aspx) that provides no documentation (and it not an ornithological organization anyway), so who knows where this number came from. I hesitate to give credence to a perhaps unreliable source. According to BirdLife International, the global population of Red-billed Queleas has not been quantified and it gives no numerical estimate or range, but it does note that "the species is described as possibly the most abundant bird in the world." Perhaps we'll have a better idea in the near future.


**The red junglefowl is native to Bangladesh, Bhutan, Cambodia, mainland China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Pakistan, Phiippines, Singapore, Thailand, Timor-Leste, and Vietnam. Although the red jungle fowl is captured by people to eat, its forest habitat is being cut, and hybridization with domestic chickens is diminishing the population of wild red jungle fowl, the species is rated as “Least Concern” by Birdlife International, which means that it is no imminent danger of becoming threatened, vulnerable, endangered, or extinct in the wild (and if all those pressure are not enough to cause concern, you can imagine what birds in those categories are going through!). 


*** They were perhaps domesticated in multiple places independently, and it is possible that some of the diversity in types of domestic chickens stem from these independent events. It also appears that the Gray Junglefowl may have hybridized with the ancient domestic chickens, and contributed to its gene pool; the archaeological and genetic studies continue to uncover more about the history of the chicken. 


Works Consulted

• BirdLife International (2012) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/01/2012.
• “Chicken, broilers or fryers, breast, meat only, cooked, roasted.” SELFNutritionData. Accessed online January 15, 2012 at: http://nutritiondata.self.com/facts/poultry-products/703/2
• Columbia/Boone County Department of Public Health and Human Services. 2010. "Columbia’s Urban Chicken Ordinance: Frequently Asked Questions." Accessed online January 15, 2012 at: http://www.gocolumbiamo.com/Health/Documents/ChickenOrd_FAQ1-10.pdf
• “Egg, whole, raw, fresh.” SELFNutritionData. Accessed online January 15, 2012 at: http://nutritiondata.self.com/facts/dairy-and-egg-products/111/2
• FAO Stat database inquiry. Food and Agriculture Organization of the United Nations (FAO). 2012. I ran several data inquiries through “Production> Live Animals” and then selected “World + (Total)” for ducks, chickens, geese and guinea fowl, and turkeys. Accessed online on January, 15, 2012 at http://faostat.fao.org/
• Glatz, P., K. Critchley, M. Hill, and C. Luna. 2009. "The Domestic Chicken." Australian and New Zealand Council for the Care of Animals in Research and Teaching Ltd (ANZCCART) Fact Sheet. The University of Adelaide. Accessed online January 15, 2012 at: http://www.adelaide.edu.au/ANZCCART/publications/A11_DomesticChickenFactSheet.pdf
• LaBadi, KT. 2008. “Residential Urban Chicken Keeping: An Examination of 25 Cities” Urbanchickens.org Website. Accessed online January 15, 2012 at: http://urbanchickens.org/files/Ordinance%20research%20paper.pdf
• Laden, G. 2008. “The Origin of the Chicken.”  ScienceBlogs.Com. Accessed online January 15, 2012 at http://scienceblogs.com/gregladen/2008/02/the_origin_of_the_chicken.php
• Roberson, D. "Pheasants and Allies: Phasianidae." Bird families of the World. Accessed 20 January 2012. http://creagrus.home.montereybay.com/pheasants.html
• University of Illinois Extension. 2012. "What is a chicken?" Incubation and Embryology Course.  Accessed online January 15, 2012 at: http://urbanext.illinois.edu/eggs/res08-whatis.html