Beyond Natural Behavior In Animal Welfare Science

Natural behavior is behavior shown by wild members of a species or the ancestors of modern domesticated animals. These instinctive behaviors evolved for survival. Following the publication of the Five Freedoms in 1979, which included freedom to perform natural behavior as one of the five fundamental freedoms of an animal, the ability of an animal to perform natural behaviors became a widely used indicator of farmed animal welfare.

But, while some aspects of natural behavior are associated with good welfare, this paper claims, some are not. The paper argues that it is time we look beyond natural behaviors and focus more on the ‘wants’ and ‘needs’ of modern-day farmed animals to assess their welfare more objectively.

In the 1960s, Niko Tinbergen proposed that the four questions we should ask about any behavior are:

• How did the behavior develop (ontogeny)?
• How does the behavior help an animal to survive and reproduce (adaptation)?
• How has the behavior changed over evolutionary time (phylogeny)?
• What are the neural, hormonal, and other mechanisms underlying the behavior (causation)?

Through reflecting on these questions, the author says, it is possible to begin to ask the most important question when looking to provide good welfare: what is it that actually matters to the animal?

The idea of ‘natural behavior comes from an outdated model in which animals have instinctive urges which they have the drive to pursue. The longer they’re denied the ability to pursue an instinctive urge, according to this theory, the more intense their desire to pursue the urge becomes. While that model does accurately describe some aspects of animal behavior, such as sleeping for a long time after sleep deprivation, it’s limited.

Asking Tinbergen’s questions about causation and ontogeny allows us to understand animal behavior better. In reality, animal behavior is learned. Genes control what an animal finds rewarding or punishing, but animals learn from experience how to pursue things they find rewarding and avoid things they find unpleasant. 

Because of the development of behavior studies over the last 60 years, finding out what matters to an animal is now possible. Useful techniques include:

• Observing where an animal spends time and for how long.
• Observing whether an animal moves quickly or slowly toward a particular situation.
• Offering an animal a choice between two or more options.
• Conditioning an animal to associate a particular place with an experience, and then observing whether the animal avoids or seeks out that place.
• Teaching an animal to perform a particular behavior in exchange for a reward. 

The author also argues that it’s useful to ask Tinbergen’s questions about the adaptive value and phylogeny of behaviors. In order to understand the behaviors of today’s domesticated animals, we need to understand the behaviors of their ancestors. Domesticated animals often still value behaviors that were critical to the survival of their ancestors. For example, jungle fowl roosted in trees to avoid predators, and domestic chickens seek out the ability to roost. Ancestral behaviors can help explain why domesticated animals sometimes behave in a way that is harmful to them. Animals may eat too much food because their ancestors evolved in an environment where food was scarce. Adaptation is different from causation: animals might have evolved to eat quickly to preserve their health, but they’ll still eat quickly when it is bad for their health. 

Phylogeny is also important because humans have artificially bred domesticated animals for particular traits. Because domesticated animals are different from their wild ancestors, they may not want the same things or perform the same behaviors as their ancestors. The phylogeny of domestic animals is little-studied, which the author believes is a mistake.  

Even though the author believes we should find other ways beyond natural behaviors to measure ‘good’ animal welfare, this is not to say we should completely disregard the behaviors displayed by the ancestors of modern-day farm animals. Some of these behaviors can be a sign of good welfare or can answer our questions about why animals behave in certain ways. But the complexity of animal behavior must be acknowledged and addressed. Domestic animal welfare needs an evidence-based approach that measures what actually matters to the animals themselves.