Chicken Behavior: An Overview of Recent Science

chicken behavior infographic

Sources cited in this infographic can be found at the bottom of the page

A Revolution in Our Understanding of Chicken Behavior

What we’ve learned about the avian brain and behavior in just the last 15 years contradicts hundreds of years of misinformed views about chickens and other birds. Much of what was previously thought to be the exclusive domain of human / primate communication, brain and cognitive function, and social behavior is now being discovered in chickens and other birds. It’s nothing short of a revolution in our understanding of chickens!

Recent scientific research into chicken behavior confirms what many who have observed chickens closely for years have long known to be true: chickens are far more intelligent and cognitively sophisticated than previously believed. While intelligence level is not a morally relevant criteria for how we treat others, these findings can help us debunk long-standing prejudices and harmful stereotypes about chickens that contribute to their utterly abysmal status in our society. To be frank, we treat them like unfeeling and unthinking objects. In fact, chickens and turkeys combined represent 99% of all animals killed for food in the U.S. Some 8.7 billion chickens in the U.S. and some 40 billion globally are slaughtered each year at only six weeks of age.

One of the most striking discoveries we made in researching this subject is that the modern domesticated chicken, contrary to popular belief, has much in common with the wild jungle fowl from which he descends. As author Annie Potts points out, “Despite the different circumstances between wild and domestic fowl, their behaviours, when permitted natural expression, remain very similar.” (1) This contradicts the common belief that natural behaviors and desires have been essentially “bred out” of the domestic chicken.

Chicken Behavior and Chicken Communication

Chickens have over 30 distinct vocalizations that communicate a wide range of information pertaining to territory, mating, nesting, distress, danger or fear, contentment and food discovery. (2)

A January, 2013, feature story in The Scientific American called The Startling Intelligence of the Common Chicken opens by explaining that the chicken “can be deceptive and cunning, that it possesses communication skills on par with those of some primates and that it uses sophisticated signals to convey its intentions. When making decisions, the chicken takes into account its own prior experience and knowledge surrounding the situation. It can solve complex problems and empathizes with individuals that are in danger.”

The lead researcher and co-author of the SA article, Carolynn L. Smith, has also published numerous in depth scientific reports of her study of chicken behavior such as The Chicken Challenge: What Contemporary Studies of Fowl Mean for Science and Ethics (August, 2012), and she is also featured in the recent documentary, Thoughtful Birds in Action (watch here by clicking on title). Among the many striking findings of her work, Smith provides multiple examples of how chickens use highly complex forms of “communication using signals that are functionally referential and representational,” a form of communication observed in many primates and some birds, such as ravens and chickadees. One example of this kind of communication is how males entice females with food as a form of courtship that does not immediately lead to mating. This means that females, not only take their time to eavesdrop and evaluate the males’ behavior, but they also must form an opinion about various males — and their reputations for providing food — and then commit these various experiences to memory. Only then does the female express a mating preference.

Another example Smith offers is how more submissive males in a flock use clever and deceptive strategies to court females while diverting attention away from the dominant male who would otherwise derail their plans. The objective is to outsmart the dominant male by attracting a potential mate away from him without him getting wise to the submissive male’s intentions. And this strategy often succeeds!

Potts cites the example of chickens responding to calls indicating the presence of novel food but not so much to food calls about known food. “Thus it now appears that the cognitive processes involved in representational thinking in chickens are similar to those required for associative learning in humans.” (3)

Carolynn ‘K-lynn’ Smith, PhD, Department of Brain, Behaviour and Evolution, Macquarie University, Australia

Carolynn ‘K-lynn’ Smith, PhD, Department of Brain, Behaviour and Evolution, Macquarie University, Australia

Chicken Behavior and Their Social World

A hierarchal order is very important to the social lives of chickens. The head rooster protects the territory the group inhabits, as well as the chicks and hens in the group. Groups are composed of more dominant hens who remain close to the head rooster as well as more submissive hens and roosters who keep closer to the periphery. Roosters display a number of courting rituals to attract mates. Hens are attracted to roosters based on both their physical and behavioral characteristics. The pecking order, once established, maintains order and stability within the group.

Additionally, Smith identifies specific chicken behaviors that demonstrate their complex social world, including:

  • self-assessment or making comparisons between themselves and others in a group: “Chickens demonstrate an awareness of themselves as separate from others”
  • learning from others in a group: “Chicks gain information about palatable food from their mother and she in turn changes her behavior in response to the competency of her chicks.”
  • recognition of the social status of numerous individuals in a group, widely accepted as a measure of logical reasoning ability
  • Chickens communicate on many levels, through vocalizing and even body language. photo: Marji Beech

    Chickens communicate on many levels, through vocalizing and even body language. photo: Marji Beach

    socially-dominant individuals tend to be group leaders from which the others learn, most likely through imitation or emulation

  • behavioral flexibility, the ability to deviate from established routines to solve novel problems, including innovation (i.e., novel solutions to environmental or social problems), social learning (the acquisition of information from others), and tool use
  • long-term relationship-building that requires long term memory
  • ability to coordinate group activities such as foraging and group defense

Connecting the Dots: Chickens, Primates and Humans

An article in Science Daily called Bird brain? Birds and humans have similar brain wiring (July, 2013) presents the findings of a research team at the Imperial College London who found that “areas [of the brains of humans and birds] important for high-level cognition, such as long-term memory and problem solving, are wired up to other regions of the brain in a similar way.” Professor Murray Shanahan, author of the study, wrote: “Birds have been evolving separately from mammals for around 300 million years, so it is hardly surprising that under a microscope the brain of a bird looks quite different from a mammal. Yet, birds have been shown to be remarkably intelligent in a similar way to mammals such as humans and monkeys.”

Lesley Rogers, Emeritus Professor of Neuroscience at University of New England, has made outstanding contributions to understanding brain development and behavior. She discovered lateralization in the chick forebrain, when lateralization was still believed to be a unique feature of the human brain. Later it became known that hemispheric specialization is ubiquitous in the animal kingdom.

Lesley Rogers, Emeritus Professor of Neuroscience at University of New England, has made outstanding contributions to understanding brain development and behavior. She discovered lateralization in the chick forebrain, when lateralization was still believed to be a unique feature of the human brain. Later it became known that hemispheric specialization is ubiquitous in the animal kingdom.

Yet, as many animal ethicists and behavioral experts point out, there are problems with these comparisons that prevent us from a more authentic understanding of how chickens think and feel. Karen Davis, Ph.D., president of United Poultry Concerns, has presented a tremendously thought-provoking analysis of cross-species comparisons in her article entitled, Are Chickens Smarter Than Toddlers? A View of Cross-Species Comparisons. Leading avian neurologist and researcher Lesley Rogers argues that instead of ranking animals according to a simplistic, anthropocentric model of intelligence, we would be more accurate and just in our assessments if we recognized that there are many different measures and kinds of intelligence. And evolutionary biologist Marc Bekoff explains in his article, Are Pigs as Smart as Dogs and Does it Really Matter?, that such comparisons are silly and dangerous, as if to suggest dumber animals suffer less than smarter ones.

Moreover, we’ll never be able to know for certain what forms of intelligence other animals might possess that could simply be outside of human understanding. As author Annie Potts explains, “While chickens display feelings comparable to those of humans (such as grief, fear or happiness), they no doubt also possess their own exceptional forms of emotion and consciousness that even the most rigorous scientific tests may not begin to uncover — simply because these inimitable perspectives of chickens do not register conceptually or experientially within the human domain.” (4)

chicken behavior, chickens raising their young

photo: Willowite Animal Sanctuary

Chicken Behavior and Emotions

Emotional intelligence is yet another measure of cognition or awareness in animal minds. Science aside, most of us can easily identify emotions in animals we are close to like dogs or cats. And those of us who spend a lot of time around chickens see a visceral and diverse expression of emotions, yet our society still generally doesn’t believe that chickens express emotional states and act on their emotions. But in the case of chicken behavior and emotions, science is proving popular opinion wrong. A Spring, 2011 study from the University of Bristol (5) gained important new insight into the minds of domestic hens, discovering, for the first time, that they show a clear physiological and behavioral empathic response to their chicks.

“We found that adult female birds possess at least one of the essential underpinning attributes of ‘empathy’; the ability to be affected by, and share, the emotional state of another,” reported Jo Edgar, PhD student involved in the Bristol study. The research team believes this finding is of great importance since chickens in modern agriculture are routinely forced to witness pain, suffering and death of other flock mates. Such witnessing of trauma and distress could exacerbate the already deplorable conditions in which these animals are forced to live.

Chicken Behavior and Memory

Those of us who observe chickens on a daily basis see their memory and recall in action in a wide variety of everyday situations. Recent science tell us that chickens recognize over 100 individual faces even after several months of separation. They also confirm that chickens consider the future and practice self-restraint for the benefit of some later reward, something previously believed to be exclusive to humans and other primates.

As stated earlier, chickens do not just learn through trial and error. They retain what they’ve learned from past experiences, then recall and apply what they’ve learned in future situations. Researcher Andy Lamey of Monash University in Australia released the findings of his study of chicken behavior in May of 2012. An important part of this study involved the observation of mother hens and their chicks, specifically, how and what the mother hens taught their young about edible food items, what and how the chicks learned (and retained what they learned), and how the mother hens then modified their teaching based on the progress of their chicks’ learning.

chicken behavior: chicks in studyIncredibly Precocious Chicks

One recent high profile study of chicken behavior by 20-year veteran researcher Christine Nicol (University of Bristol) credits chickens with the ability to perform complex skills within days of hatching, such as basic arithmetic, self control and basic structural engineering — skills that don’t develop in humans until their toddler years. The mass media turned these comparisons into catchy headlines, like Can chickens REALLY be cleverer than a toddler?

Ethologist Dr. Giorgio Vallortigara of the University of Trento, Italy, is widely recognized as a pioneer in chicken behavior and cognition research, specifically with newly hatched chicks. His work demonstrates how chicks are born with an understanding of basic arithmetic, geometry and physics, advanced problem-solving, and quick learning and retention. Italian psychologists Rosa Rugani, Lucia Regolin and Vallortigara showed chicks prefer to join groups of more objects (4) over a single object or a smaller set of objects. The chicks in these studies were found to imprint (bond) with these “objects” as if they were their mothers or flock mates. ”The most complex numerical ability is to manipulate numbers by performing simple arithmetic. We know rhesus monkeys can do this and we know that five-day-old chicks can too,” explain these researchers.

In a recent interview with Uncooped, Vallortigara explains “Basically, I use the young domestic chicks to investigate the origins of knowledge; I’m interested in core knowledge abilities like number, space, time and cause, and I am trying to clarify how much of these abilities are already available at birth, before interactions with objects of the world may have shaped them through learning and experience. We found that indeed newly hatched chicks do possess surprisingly sophisticated abilities at birth, they know about basic principles of physics (such as solidity), could perform basic arithmetic (with small numerousness), they can deal with the geometry of enclosed surfaces to orient and navigate….”

chicken behavior, egg laying hens

“Enriched colony cages” for egg laying hens in European farm. Thi is the new “ethical” standard for hens. They look as miserable here as the ones stuck in the old cage system. photo: Jo-Anne McArthur

How Science Can Drive Ethics

While some scientific researchers appear reluctant to extrapolate the ethical implications of their work in chicken behavior, many of them now identify how routine chicken farming practices present serious ethical problems. From the hatching stage through the raising and slaughtering of chickens, the science presented here confirms that chickens exploited for meat and eggs endure a staggering degree of physical and psychological suffering.

Neuroscientist Lesley Rogers, author of Development of the Brain and Behaviour in the Chicken, argues that we are compelled to understand the cognitive abilities of chickens above all other birds because they are the most exploited and least respected avian species. Even Vallortigara, who claims to see no ethical implications from his discoveries, nonetheless makes a clear ethical judgment when he says, “I would urge people to treat chickens with respect even if they were not intelligent as they are.”

Moreover, the exploitation of some 40 billion chickens every year when we have no biological requirement for animal flesh is morally indefensible. When we can easily make choices that do not harm these animals, then we should, as Karen Davis so eloquently articulates in her article, Eliminating the Suffering of Chickens Bred for Meat.

Ethical Impacts of Chicken Behavior Research

Much of the research on chicken behavior and biology is motivated by the poultry industry’s objective to more efficiently exploit chickens as a resource. As author Annie Potts points out in her book Chicken, “It is no coincidence that the first creature to have a full genome map was the chicken: Gallus is the most studied species in the world. Every biological feature was experimented on with the aim of rendering chickens more serviceable to humans.”

Free from Harm opposes animal breeding and exploitation (which includes animal testing), and we recognize that even observational studies, conducted in as natural an environment as possible to encourage natural behavior, present their own ethical problems. Aside from these ethical challenges, observational studies of chicken behavior that are intended to benefit the species, rather than the industry that exploits them, may have great value in changing society’s attitudes toward chickens. The birds in such studies are spared lives as agricultural commodities. And some researchers work to rehome animals to sanctuaries or to private individuals who will care for them as companions.

chicken behavior: our attitude about chickens like this hen

photo: Robert Grillo

Chicken Behavior Beyond Science

While science provides important empirical validation to our understanding of chicken behavior, anyone with an inquisitive mind and an interest in chickens can learn a great deal about them just by observing and interacting with them. In a short time, their individual personalities and rich life experiences are revealed.

Free from Harm has documented each of its chicken rescues, using photos, videos and stories to provide an intimate portrayal of each chicken we’ve had the pleasure of getting to know. Karen Davis has also offered a very compelling chronicle of her years of experience with the rescued birds on her sanctuary in her essay, The Social Lives of Chickens. A future article will focus on learning about chicken behavior through sanctuaries.

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All online source are hyperlinked where applicable. The following are print sources followed by key online sources used in this article.

(1) Annie Potts, Chicken. London: Reaktion Books, 2012. p. 40

(2) Ibid, p.44

(3) Ibid, p. 48

(4) Ibid, p. 40

The Startling Intelligence of the Common ChickenScientific AmericanVolume 310, Issue 2

United Poultry Concerns

Are Chickens Smarter Than Toddlers? A View of Cross-Species Comparisons

Avian maternal response to chick distress’, J L Edgar, J C Lowe, E S Paul, C J Nicol, published online ahead of print Proceedings of the Royal Society B, 9 March 2011.

Rugani, Rosa, Regolin , Lucia, Vallortigara, Giorgio, Imprinted numbers: newborn chicks’ sensitivity to number vs. continuous extent of objects they have been reared with, Developmental Science, September 2010, Volume 13, Issue 5, pages 790–797

Smith, Colin, Bird brain? Birds and humans have similar brain wiring, Science Daily, (Imperial College London), 2012

The Startling Intelligence of the Common ChickenScientific AmericanVolume 310, Issue 2

Smith, Carolynn L. and Johnson, Jane, The Chicken Challenge: What Contemporary Studies of Fowl Mean for Science and Ethics, Between the Species,  Vol. 15 (2012)

United Poultry Concerns

Uncooped (The National Museum of Animals & Society)

Sources for “Chicken Minds” Inforgraphic

1. Rogers, Lesley J., The Development of Brain and Behaviour in the Chicken. Wallingford, Oxfordshire, 1995. p. 231.

2. Smith, Colin, Bird brain? Birds and humans have similar brain wiring. Science Daily (Imperial College London), 2012

3. Marian Stamp Dawkins, What Are Birds Looking At? Head Movements and Eye Use in Chickens, Animal Behaviour, IXIII (2002) pp. 991–8.

4. Rugani, Rosa, Regolin , Lucia, Vallortigara, Giorgio, Imprinted numbers: newborn chicks’ sensitivity to number vs. continuous extent of objects they have been reared with, Developmental Science, September 2010, Volume 13, Issue 5, pages 790–797

5. Smith, Carolynn L. and Johnson, Jane, The Chicken Challenge – What Contemporary Studies Of Fowl Mean For Science And Ethics, Between the Species,  Vol. 15 (2012) > Iss. 1, p. 84

6. G. McBride et al, ‘The Social Organization and Behavior of the Feral Domestic Fowl’, Animal Behavior Monographs, n (1969), p.25

7. Wood-Gush and Duncan, ‘Behavioral Observations in Domestic Fowl,’ p.255

8. Smith, Carolynn L. and Johnson, Jane, The Chicken Challenge – What Contemporary Studies Of Fowl Mean For Science And Ethics, Between the Species,  Vol. 15 (2012) > Iss. 1, p. 89

9. Specter M, “The Extremist,” The New Yorker, April 14, 2003, p. 64.

10. Smith, Carolynn L. and Johnson, Jane, The Chicken Challenge – What Contemporary Studies Of Fowl Mean For Science And Ethics, Between the Species,  Vol. 15 (2012) > Iss. 1, p. 82

11. Ibid, p. 86

12. Annie Potts, Chicken. London: Reaktion Books, 2012. p. 44

13. Rogers, Lesley J., The Development of Brain and Behaviour in the Chicken. Wallingford, Oxfordshire, 1995. p. 48

14. Smith, Colin, Bird brain? Birds and humans have similar brain wiring. Science Daily (Imperial College London), 2012, p.82

15. Ibid, p. 76

16. D.G. Griffin, Animal Minds: Beyond Cognition to Consciousness (Chicago, 2001), p. 173

17. Beaugrand, J. P., M. E. Hogue, and P. C. Lague. 1997. “Coherent Use of Information by Hens Assisting to the Victory or Defeat of Their Former Dominant by a Stranger: A Case of Transitive Inference?” In Processus cognitifs et ajustement écologique, edited by Société Francaise pour

l’Étude du Comportement Animal, 131–137. Toulouse, France: Presses de l’Université Paul Sabatier.

18. Dunbar, R. I. M., and Susanne Shultz. 2007. “Evolution in the

Social Brain.” Science 317: 1344-1347.

19. Nicol, Christine. 2006. “How Animals Learn from Each Other.” Applied Animal Behavior Science 100: 58-63.

20. ‘Avian maternal response to chick distress’, J L Edgar, J C Lowe, E S Paul, C J Nicol, published online ahead of print Proceedings of the Royal Society B, 9 March 2011.

21. Davis, Karen PhD, The Social Life of Chickens, Columbia University Press, 2012

22. Annie Potts, Chicken. London: Reaktion Books, 2012, p. 46–52

23. Ibid.

About Robert Grillo

Robert Grillo is the founder and director of Free from Harm, a non profit animal rescue, education and advocacy organization. Robert is the author of over 500 articles on Free from Harm and is particularly interested in the advocacy of chickens and turkeys who collectively represent 99% of the animals exploited for food. He shares his life with a flock of rescued hens and a rescued homing pigeon. You can email Robert at robert@freefromharm.org. And you can find him on Google+ and Twitter.

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