Do Chickens Have Feelings, Emotions, and Sentience?
Do chickens have moods, emotions, and expressions?
Reading Time: 7 minutes
How far do we go in caring for our chickens? Do chickens have feelings? Should we be concerned by displays of emotion? Are they sentient (aware of pleasure or pain)?
We cannot directly experience the feelings of chickens, other animals, or even other people, although at least humans can tell us about it. For animals, we have to interpret their behavior, body processes, and brain structure to attempt to understand how they experience their situation. We cannot rely entirely on human interpretation of behavior, because our needs and motivations vary from those of other animals and we can only see things from a human perspective. It is hard for us to imagine life from a chicken’s point of view, and we may never know if chickens have feelings in the way that we do.
Scientific research attempts an objective view by measuring and comparing animal responses and choices. In this way, we learn what animals need, prefer, and can cope with in order to live a pleasant life. Researchers are in the process of identifying signs that correspond to positive or negative emotions and the intensity of those emotions. Research is in its infancy, but there is clear evidence that chickens have complex mental processes. There is growing evidence that chickens experience emotions that matter to them and affect their health and welfare.
Are Chickens Sentient and Could They Have Feelings?
Although it cannot be measured or proven, scientists widely agree that mammals and birds are sentient, being aware of their perceptions, experiences, and emotions. Christine Nicol, Professor of Animal Welfare at the Royal Veterinary College in London, England, specializes in chicken behavior. She states that there is “… no good reason based on brain structure to exclude the possibility of conscious experience in these birds.”
She explains, “… in humans at least, primary conscious experience (the feeling of seeing something, for example) appears to depend on a rapid relay of information between the thalamus and cortical regions. All healthy mammals and birds (at least those beyond a certain stage of embryonic development) possess the neural circuit patterns that should support similar types of experience …”
Chickens’ Emotions: the Basis of Feelings
Nicol and her colleagues at the University of Bristol have spent many years exploring hens’ motivations and preferences to find out what they need for comfort and well-being. They have also matched behaviors with physiological measurements (such as stress hormones and eye/comb temperature) to find visible signs of their emotional experience.
Some basic emotions result in obvious signs that are common to humans and other animals: we all evoke the fight or flight response as a survival mechanism in the face of danger. Food is an attraction highly valued by all animals and can be used as a benchmark by which to measure other motivations. We can build on this to learn what brings distress or contentment. It is important to avoid distress, as prolonged stress leads to poor health. Moreover, positive emotions enable animals to cope better with change and stressful events.
Pain and Malaise
Chickens tend to hide signs of pain and disease to avoid attracting the attention of predators. Nevertheless, they reduce activity to save energy for the healing process and rest in a huddled posture. Although they feed less, they may take in more of a high-energy source, such as mealworms.
Fear
Chickens are susceptible to fear caused by sudden movement and noises, capture, and novel objects and environments. Their cautious demeanor and readiness to flee protects them from predators when they are out at range, but can lead to accidents in enclosed spaces. Once trapped by a predator, playing dead may be the best policy. The immobility you witness when you pick up or corner a chicken reflects the level of fear they are experiencing. Stress hormones increase in these situations (as in humans) and the brain structures involved are similar to those in mammals.
If chickens are allowed to escape, hide, or otherwise reduce the threat, they can recover. Having the ability to take evasive action gives them the relief that a measure of control over their environment brings. However, continual exposure to frightening events beyond their control can lead to passive behavior, increased fearfulness, and distress. Predictability can help to reduce this effect. Consequently, some chicken farmers give advance warning of their arrival with gentle sounds to avoid frightening the birds.
Stress and Distress
Brief unpleasant events cause little harm, especially if they are predictable or controllable. However, prolonged stress can be very damaging. Initial signs are subtle, such as rapid switching between activities, giving an impression of agitation. This can be observed in barren pens that offer little activity and comfort. Long-term poor welfare can result in repetitive, futile habits, such as pacing and feather pecking.
Anxiety and Depression
Once chickens have learned to associate a signal with an unpleasant event, they display alert and agitated behavior. Such anticipation of a negative experience can be interpreted as anxiety. When chicks are isolated, they make distress calls, which could be fear or anticipation of danger. Normally, these calls bring mother hen to their rescue. Scientists have found that anti-anxiety drugs decrease chicks’ rate of calling (don’t try this at home!), suggesting a similarity to human experience.
After about an hour of isolation, chicks become quiet and inactive. This state is likened to depression, as its onset is slowed or reduced by anti-depressants. Interestingly, an enriched environment also helps counter the onset of depression. Anxious or depressed chicks tend towards a pessimistic mood, making them wary of ambiguous situations and slower to approach a potential reward.
Anticipation and Curiosity
Conversely, chickens’ ability to anticipate can result in pleasant emotions. The species spends considerable time every day foraging and exploring. Even when given easily accessible feed, they prefer to scratch and examine the dirt and wander off in quest. The actual activity of foraging seems to be rewarding in itself (as it is to humans and other mammals). Chickens trained to associate a sound with imminent delivery of mealworms became more alert and displayed more preening and wing flapping. These comfort behaviors are shown more often in positive welfare situations. Chickens sometimes emit a rapid burst of clucks when finding food, and also in anticipation of other rewards.
Frustration
The inability to access a needed resource or perform a vital behavior leads to frustration. Initially, chickens may perform other irrelevant behavior to distract themselves from their thwarted motivations, and this is termed “displacement”. For example, chickens unable to access feed or water may preen or peck the ground. When confined, chickens may pace and make distinctive noises: whines and a series of long, wavering moans, termed “gakel”. Frustration may be vented by aggressive pecking and, as with any long-term stress, can lead to behavioral issues.
Feelings of Deprivation
Cages restrict space and the ability to perform natural behaviors, and their occupants often show signs of deprivation. For example, when chickens cannot dust bathe, they go through the motions using feed grains or nothing at all. Then when given the chance, dust bathing becomes a priority. They also spend a lot of time searching and giving the gakel call when they cannot find a suitable place to lay.
Love and Empathy
Although chickens prefer to flock with familiar companions, there is no evidence of friendship bonds between adults. Social intelligence in chickens is highly complex but appears to lack the emotional complexity seen in mammals, such as goats and donkeys. On the other hand, mother hens show strong attachment to their chicks and become flustered if they witness their brood experiencing unpleasant circumstances. Hens respond to their chicks’ distress calls instinctively. But they also apply their own knowledge of an experience to what they see their chicks going through.
An experiment demonstrated this clear sign of empathy. When each hen saw her chicks entering a box where she believed a puff of air would be blown at them, she became alert and increased her calls, while her heart rate increased and comb cooled (indicating stress). She did not do the same when witnessing adult companions in danger of the puff. However, nine-week-old chicks mirrored the responses of their brood-mates who received a puff of air, by freezing and lowering eye temperature (suggesting fear). Chickens, like many other animals, become afraid when they witness one of their number in distress.
Much more is to be learned about chickens’ emotions and how they show them. Fortunately, research is ongoing, so that we may be better able to identify how chickens feel.
Sources
- Nicol, C.J., 2015. The Behavioural Biology of Chickens. CABI.
- Interview with Professor Christine Nicol for the Sentience Mosiac.
- Edgar, J. L., Paul, E. S., and Nicol, C. J. 2013. Protective mother hens: cognitive influences on the avian maternal response. Animal Behaviour, 86, 223–229.
- Edgar, J.L. and Nicol, C.J., 2018. Socially-mediated arousal and contagion within domestic chick broods. Scientific Reports, 8(1), 1–10.
- *McGrath, N., Dunlop, R., Dwyer, C., Burman, O. and Phillips, C.J., 2017. Hens vary their vocal repertoire and structure when anticipating different types of reward. Animal Behaviour, 130, 79–96.
Originally published in the August/September 2021 issue of Backyard Poultry and regularly vetted for accuracy.
