While the perennial debate concerning the origin of Gallus gallus domesticus (or as theyre more commonly known chickens) has raged unchecked amongst bar-stool scholars and coffee house philosophers for decades, it was only fully explored and quantified with a possible solution when Neil Degrasse Tyson examined it in detail. Did he know where chickens came from, do we know what they are? Are chickens mammals or reptiles?
His theory that the egg appeared first but it was laid by another bird didnt really shed as much light on the debate as wed hoped it would and it carefully circumvented the need to provide an actual answer. The lack of a definitive conclusion means that, realistically, were still no wiser about which came first, the chicken or the egg.
A popular theory among evolutionary biologists and paleontologists is that, unbeknownst to us, dinosaurs still roam the Earth. Or more accurately, their ancestors do.
The idea that birds are the direct descendants of dinosaurs initially began to gain momentum when Thomas Henry Huxley, often referred to as “Darwins Bulldog” due to his strict adherence to and defense of the Theory of Evolution, discovered a fossilized feather and suggested that there might be a direct genetic link between birds and dinosaurs, albeit one separated by millions of years of development.
It was a theory that was seized upon at the time and despite being more than one hundred and fifty years old, is still the cause of fervent discussion and discourse in the scientific community.
Still lacking the rosetta stone that would either prove or disprove Huxleys hypothesis, the idea slowly crept into and became part of, the mainstream consciousness, which in turn gave rise to the idea that birds were more closely related to lizards than they are to mammals.
Which, no doubt, originally led to the question in hand, namely “Are chickens mammals or reptiles?”
So, what are they? Are Chickens Mammals or Reptiles?
To get straight to the point, chickens are not reptiles or mammals. They are members of the genus Fowl, which is a subclass of the biological class Aves, or birds.
a class of warm-blooded vertebrates distinguished by their strong, light skeletons, feathers, toothless beaked jaws, high metabolic rates, and four chambered hearts
Chickens are members of the subgenus (or species) of birds known as fowl, which has a unique set of traits that set it apart from the rest of its biological family. Compared to the average Aves family member, fowl are far more prolific and frequently produce, or lay, batches of five to ten eggs as opposed to the much more common one or two eggs that larger birds of prey typically lay.
In addition, the young grow considerably faster than other Aves species members, reaching maturity and the capacity to procreate at significantly younger ages in most cases.
Although they are distinct from both mammals and reptiles, birds and the Aves family as a whole have a surprising amount in common with both.
In order to definitively refute the claims that chickens are neither reptiles nor mammals, we will examine the characteristics of each and show how chickens are incompatible with both biological categories.
Origin and dispersal
A single domestication event of the red junglefowl in modern-day Thailand gave rise to the modern chicken, with only minor transitions separating the modern breeds, according to an early study. [44] The red junglefowl is uniquely suited to maximize its own procreation by utilizing the enormous amounts of seed generated at the conclusion of the multi-decade bamboo seeding cycle. [45] Humans domesticated chickens by taking advantage of the red junglefowl’s propensity for prolific reproduction in response to an increase in food sources. [46].
Exactly when and where the chicken was domesticated remains controversial. According to genomic studies, chickens were domesticated in Southeast Asia some 8,000 years ago[42] and then spread to China and India between 2,000 and 3,000 years later. Domestic chickens were present in Southeast Asia well before 6000 BC, China by 6000 BC, and India by 2000 BC, according to archeological evidence. According to a groundbreaking 2020 Nature study that completely sequenced 863 chickens worldwide, all domestic chickens descended from a single domestication event of red junglefowl, which is primarily distributed in southwestern China, northern Thailand, and Myanmar today. Due to their interbreeding with native wild species of junglefowl, these domesticated chickens spread throughout Southeast and South Asia, creating geographically and genetically distinct groups. The White Leghorn breed, which is the most widely produced commercial variety, has a mosaic of diverse ancestries that it inherited from red junglefowl subspecies. [49][50][51].
Use by humans
With a population of 23, chickens are a common and widespread domestic animal. 7 billion as of 2018 . [68] Every year, over 50 billion chickens are raised for their meat and eggs. [69] More than 8 billion chickens are killed annually for meat in the United States alone. [70] Additionally, over 300 million chickens are raised for eggs. [71] Factory farms raise the vast majority of poultry. As per the Worldwatch Institute, this method accounts for %2074% of the global poultry meat and %2068% of the global egg production. [72] An alternative to intensive poultry farming is free-range farming. Conflict between these two primary approaches has resulted in persistent problems with ethical consumerism. Intensive farming’s detractors claim that it is cruel, hazardous to human health, and detrimental to the environment. [73] Proponents of intensive farming claim that because of their productive methods, which preserve land and food supplies, and the fact that the animals are cared for in a controlled atmosphere, [74] Chickens farmed for meat are called broilers. The average time for broiler breeds to reach slaughter size is less than six weeks [75], with free-range and organic broilers requiring an additional few weeks. [76] A commercial chicken house that raises broiler pullets for meat, featuring open sides.
Chickens farmed primarily for eggs are called layer hens. Every day, more than 34 million eggs are consumed in the UK alone. [77] Some breeds of hens can lay more than 300 eggs a year; the highest recorded egg-laying rate is 371 eggs in 364 days. [78] Commercial hens lose their ability to lay eggs after a year of laying, to the point where the flock becomes unprofitable. The life expectancy of hens, especially those raised in battery cage systems, has been observed to have decreased from approximately seven years to less than two years. These birds are occasionally weak or have lost a large portion of their feathers. [79] Laying hens are then killed and sold as soup hens in the UK and throughout Europe, or they are used to make processed foods. [79] To stimulate egg-laying again, flocks in certain other nations are occasionally forced to moult instead of being killed. This entails complete abstinence from food (and occasionally water) for a period of 7E2%80%9314%20days[80] or long enough to result in a body weight loss of 22.5 to 33.5 kg, [81] or up to 22.8 days in experimental conditions. [82] In addition to encouraging the hen to shed her feathers, this also restarts the hen’s egg production. Some flocks may be force-moulted several times. In the United States, more than 25 percent of all flocks were moldered in 2003. [83].
FAQ
Do chickens count as birds?
Is a chicken a bird yes or no?
What animal category is a chicken?
Is a chicken warm-blooded?