A Need For Appropriate Challenge In Environmental Enrichment

Imagine a life without challenges: every day the same routine, without any new experience, new information, same food prepared in the same way. A life without opportunities or problems for you to overcome. Such a life would be rather dull and boring, lacking the satisfaction of personal development and growth. Could this also be the case for animals? Animals living in the wild have to face many challenges. Think of predation, social competition or finding a partner to produce offspring. Also, the environment itself set many challenges for the animals: weather, illness, and food and water availability. On the contrary, animals in captivity often live in an environment which is simple, predictable and monotonous. Challenges are limited and infrequently or not present at all. You might expect that it is relaxed for the animal and that it can enjoy its life. But is it? Might animals suffer from a lack of challenge in their life? In this article, I want to accentuate the importance of ‘appropriate’ challenge in environmental enrichment. 

How do animals deal with challenges? 

Whereas social stress, hunger and illness are serious challenges in the life of an animal, it is out of focus when talking about environmental enrichment. Proper nutrition and veterinary care should prevent or cure these challenges, and these challenges are pretty complex, and often not ethical or acceptable, to recreate in captive environments. Also, in zoos, we try to house animals in natural social situations. In this article, we focus on the challenges induced by novelty. But how do animals deal with challenges? 

When we turn to wild animals, we see that they are adapted to turn natural challenges into opportunities by mastering a specific task, or by flexibility in behavioural response. For an animal to deal with such a challenge is centred around two key concepts: Competence and agency. Let me explain. 

Competence and agency

Competence is defined as the whole array of cognitive and behavioural experience, tools and strategies that an animal use at any moment to deal with novel challenges when they arise. They are partly genetically inherited from generation to generation. But on the other hand, animals learn them through interaction with the environment. It is a result of reactions to external events. However, if competence is only used when reacting to an external event, an animal’s life would be perilous. It would be a matter of luck to master skills and learn to deal with the challenge because it hasn’t learned these skills and experience yet. If it goes wrong or the wrong choices are made (because of lack of competence), it could be detrimental to its welfare or even game over. But how does an animal learn to cope with these challenges then? It may be too late to start looking for a solution when you are upfront the challenge, so it’s worthwhile that an animal invests in his future by exposing itself to a degree of risk and spend time and energy to develop these abilities and experience: agency.

Agency is defined as that an animal actively engages with the environment with the main purpose of gathering knowledge and enhancing its skills and abilities for future use. It is the intrinsic tendency to behave actively beyond the degree of the current needs and to widen their range of competencies. The animal needs to learn to become a master and to improve their coping abilities to novelty. You could say that agency is the procedural (more proactive) aspect and competence the functional (more reactive) aspect to prepare and resolve challenges. Agency is intrinsically motivated. We can see it with what we termed as contrafreeloading. Many animals do choose to make an effort to obtain food or water, even if the same type of food or quality of water is also freely available. When you give meerkats a choice between mealworms in a dish and mealworms in an enrichment device, it will often choose to engage with the enrichment instead of eating straight from the food bowl. Furthermore, it is even stated that animals enjoy the process of learning, too. It is reinforcing for animals to develop in themself.

The relation between the level of challenges and level of skills (source: Špinka and Wemelsfelder, 2011)

Problem-solving, exploration and play

Prominent facets of agency and competence are the behaviours problem-solving, exploration and play. When known behavioural solutions no longer work to attain a goal, in captivity mostly seen in obtaining food, problem-solving comes into action. Toates (2004) describes problem-solving as modifying appetitive behaviours, as well as engage higher levels of cognition control and use memories of the animal’s own past action, successes and failures to attain its goal. Multiple research shows that it also appears to have longer-term beneficial consequences for the ability to cope with the animal’s environment (Ernst et al., 2005; Puppe et al., 2007; Bell et al., 2009). 

Exploration is behaviour directly aimed at gathering information on the environment. When we place an animal in a new environment, even when features are present that are known to the animal (like its normal food, toys, etc.) it will likely first move around inspecting all kinds of stimuli in this environment. It is even seen that animals actively seek for novel stimuli, where it visits places where it can expect novel objects (Wood-Gush and Vestergaard, 1991). The information primacy theory, which describes the need for information gathering to expand its knowledge to increase understanding and survival, explains this phenomenon. The motivation for exploration, also labelled as ‘curiosity drive’, probably evolved because of the need to reduce uncertainties in the environment and bring crucial advantages for future events. 

Play, as Špinka et al. (2001) suggest, has a significant function in training for unexpected situations and mishaps. With play, an animal can practice in a known environment how to handle situations when animals lose control or forces disturb their routine. So play behaviour represents an important role in developing competence. 

How does providing challenge improve animal welfare?

How does this improve animal welfare, or in other words, why do animals need challenges? As illustrated above, creating challenges in captive environments create opportunities to express agency and develop competence. This process of excepting challenges is suggested to be rewarding and enjoyed by the animal in a certain length, like the concept of contrafreeloading. The interaction between perceived challenge and skills, which Moneta and Csikszentmihalyi (1996) labelled as ‘flow’, chase each other. If the level of challenge is higher than the level of skill, it will try to learn new skills. If skills are higher than the challenge, the animal will seek more challenge. Expression of agency seems to be self-rewarding for an animal as well. In addition, as stated above, competence and exploration increase coping abilities to novel situations and environments. Furthermore, increased opportunities to challenges increase levels of interaction and mobility, which likely have direct physical benefits, such as stronger muscles, higher endurance, or better balance, but also improve long-term physical health and fitness. 

Pole feeding for lions

What happens if we do not give enough challenge? 

Luckily many institutions that keep (exotic) animals have rich environments for their animals. But challenges in novelty, cognitive experience and/or physical challenge are not always included in their enrichment program. As illustrated in the above section makes it clear that if you restrict animals of such challenges in their environment, it can have serious implications for their welfare. Studies have shown that restrictive environments reduce behavioural diversity. A limited environment suppresses the expression of agency, which in turn result in boredom. An animal will instead spend a large amount of their time sleeping or dozing, or just lying down. They even may spend an extended amount of time sitting or standing motionless often combined with half-closed eyes, drooping heads and ears, or pressed against a wall. These behaviours are characterized as apathetic, helpless or depressed. It is also seen that certain behaviours will develop into repetitive behaviours, where they are more fixed and compulsive. These stereotyped behaviours are a coping mechanism to cope with the unsatisfying environment and lack of stimulation. 

Illustration what happens when the environment is limited and challenges are not provided (source: Špinka and Wemelsfelder, 2011)

When removing the possibility to engage actively with the environment will also remove fulfilling the intrinsic need and reward to do this. This process can absolutely affect the emotional state of the animal. However, it does not mean that every animal is negatively influenced when challenges are limited. Some animals adapt very well in a predictable environment, but it does not take away that you can better the welfare by providing these challenges. 

Furthermore, when possibilities for agency is suppressed has consequences for the animal’s competence. The animal has no opportunity to learn skills for future use. Underdeveloped competence reduces the ability to be ready to deal with challenges once they arise and act upon expectancies appropriately. The animal has not the ability to cope with the situation, what in turn present in heightened fear and anxiety when an unexpected or novel event occurs. They are overwhelmed and don’t know how to handle the situation. 

Another potential implication is the physical health and fitness of the animal. Because the animal express less active and diverse behaviours it doesn’t train it’s body, muscles, bones, endurance and balance. In the long-term, it affects the longevity of the animal in question. A higher level of stress, fear and anxiety are also known to affect the body of an animal. Studies show that this also influences the healing from injuries and consequently, the animal experience more or longer periods of pain. 

Difference between challenges provided or not in relation to animal welfare (source: Špinka and Wemelsfelder, 2011)

It makes clear that (novel) challenge is a crucial factor in the life of a (captive) animal. Suppression of challenge affects mostly the emotional state of the animal but can direct or indirectly affect the physical state as well. However, not all types and levels of challenge elicit agency and exploration equally. You can also overdo the level of challenges, especially when the animal has not yet the skills to cope with this situation. So we need to provide an appropriate level of challenge. 

Is this challenge for the young hyena too complicated?

What is and how to apply appropriate challenge in zoos?

Meehan and Mench (2007) propose the concept of appropriate challenge, a challenge that may cause frustration but are potentially solvable or escapable. If challenges are too strong (or too many) for the skills the animal posses will result in fear and therefore stops agency. On the other hand, when challenges are not up to the skill level of the animal will result in boredom. Watters (2009) states that zoo animals are most motivated to interact with enrichment that results in a reward that is neither guaranteed nor highly improbable. The level of challenge in relation to the animal’s level of skills also influences the type of agency the animal engage. High level of novelty may trigger exploration behaviours. If the animal is more confident with the situation may trigger play behaviours instead. The core focus of this concept of ‘appropriate’ challenge is the idea that animals should have the opportunity to be active participants in their environment and be provided with opportunities to empower change in the environment through their own behaviour (Meehan and Mench, 2007).

If we practicalize the above, we can divide environmental challenges roughly into two categories: Physical challenges and cognitive challenges. That these are connected and sometimes intertwined may be clear by now. Physical challenge focus on that an animal act on environmental enrichment with strength, muscles, movement and activity. Think of pole-feeding of carnivores, balance plateaus and wobbling climbing structures. Foraging enrichment typically has these physical features like food searching and consumption. However, where wild animals also need different levels of analysis when acquiring food, many enrichment programs do not include the integration of cognitive challenge in the design of food enrichment. Stimulation of foraging behaviour should include higher levels of, or activate more frequently, the cognitive mechanisms (Meehan and Mench, 2007). 

A puzzle feeder for bears as cognitive challenge. The bear need to pull down the lever to open the log for the food. (Photo credits: Sandro Chitanava, Tiblisi Zoo)

Cognitive challenges are frequently encouraged with puzzle feeders of some sort. However, to keep the cognitive component of puzzle feeders, they must be modified and updated regularly, or you need a (very) large variety of them. Otherwise, it’s just another physical challenge where you increase foraging time and locomotive activity. In addition, cognitive challenges can also be encouraged by a large amount of novelty to increase explorative behaviours. Sensory enrichment (i.e. olfactory with perfume, herbs or animal scents) is an excellent example of this, at least when there is enough variety in it. But also complete new objects to discover works very well. 

Also creating environments that are tricky in some way to such a level that full control over the animal’s movement becomes difficult, yet the risk of injury or mishap is limited, works very well as a good challenge. In many animals, these situations will first provoke explorative behaviour, but will quickly turn into play behaviour. For example, you can use slippery surfaces, shallow water, snow and ice, sloped terrains, flexible branches and swinging and wobbling structures. 

There is much to think of when it comes to implementing challenges in environmental enrichment. Still, the bottom line is that we need to integrate an appropriate level of challenges in the life of animals we care for to increase its welfare, both physically as well as mentally. 

To summarize

The core of this article is to demonstrate that challenge is important to consider in environmental enrichment. Animals need to be able to engage with their environment in a proactive way to develop skills to make them competent to deal resourceful, skilful and in a species-appropriate way to future events, but in addition, it is rewarding for animals to be able to engage with their environment, too. This intrinsic motivation to engage goes beyond its momentary and basic needs. And as we explained above, challenges are also beneficial to the health and fitness of the animal. 

Appropriate challenges need to be matched to the animal’s sensory, physical and cognitive capacities. Environmental enrichment, therefore, needs to be adjusted to the potential abilities of the animal and its current level of skills. 

When captive environments deny the opportunity to unfold their agency, it likely prevents those animals from achieving better welfare. They may be bored, develop apathy and have decreased coping abilities when they face novel situations. It could make way for fear, anxiety and stress, but also could affect the animal by developing abnormal, repetitive (stereotyped) behaviours. 

Further reading

This article is mainly inspired and based upon the study’ Environmental Challenge and Animal Agency‘ by Špinka and Wemelsfelder (2011). I can highly recommend reading this article for more in-depth information on environmental challenges for animals, included with lots of scientific examples and related studies. 

The article on ‘The free food (contrafreeloading) phenomenon: A review and analysis‘ by Osborne (1977) is also highly recommended to read. The contrafreeloading concept is mainly based on creating and applying environmental challenge for animals in captive environments. 

More about the information primacy theory can be found in the article ‘An information primacy model of exploratory and foraging behaviour‘ by Inglis, Langton, Forman and Lazarus (2001). This article gives a clear explanation of the animal’s need for gathering knowledge of its surroundings. 

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