Chicken Ethology: An Overview

Though their average stocks number more than 19 billion worldwide, domestic chickens (Gallus gallus) are one of the most oppressed animals on the planet. In the US alone, over 8 billion chickens are slaughtered annually for their meat. Most are raised on factory farms where they live in cramped conditions and are genetically manipulated to grow abnormally large at an unnaturally fast rate. As a result, they suffer a number of physical and metabolic disorders, including lameness and sudden death syndrome.

Because of chickens’ predominant status as commodities, most people rarely think about them as individuals with complex personalities. However, the author of the current paper thoroughly examined peer-reviewed research on cognition, emotion, personality, and sociality in chickens and found that they possess a number of capacities that make them just as complex as many other bird and mammal species.

The author begins by summarizing domestic chickens’ evolutionary history and phylogeny, noting the importance of this information because it is intentionally overlooked and obscured in the process of commoditization. She then summarizes leading edge chicken research in the areas of visual cognition, numerical abilities, time perception, episodic memory (i.e., ability to remember personal experiences), self-control (i.e., ability to resist immediate gratification), reason and logic, communication, social cognition (i.e., use of cognitive skills in a social setting), emotion, and personality. She concludes that chickens possess the following:

• The ability to understand visual and spatial cues, including object permanence and illusory contours
• Some understanding of numbers and basic arithmetic
• Measures of self-control and self-assessment
• Various and complex communication, including referential communication
• Some capacity for reason and making logical inferences
• The ability to perceive time and anticipate future events
• The ability to learn from their peers (i.e., social learning)
• Complex negative and positive emotions, including empathy and susceptibility to emotional contagion

The author acknowledges that scientific literature on chicken cognition and behavior is “sparse” outside of their instrumental use as food. Yet despite a lack of published studies, the author’s review here is broad and deep. As such, it could easily serve as a kind of domestic chicken fact sheet for animal advocates.

Importantly, understanding the capacities of animals like chickens can bolster our ability to empathize with them. Under the right circumstances, empathy encourages individuals to take a stand against the gross mistreatment of animals on factory farms, as well as to fight for higher, enforceable welfare standards.