Animal Welfare through Environmental and Behavioral Enrichment

Lai Chien Hsun and Chandra Shekar Menon

Introduction

Regardless of our reasons for keeping animals in captivity, their welfare must be included into any decisions we make pertaining to their husbandry. Animal welfare should not be of concern to animal rights group alone. As the caretakers of our living collection, we have a moral obligation to provide proper welfare for our animals.

In their natural environment, wild animals go through a complex developmental stage, involving countless external environmental stimuli, which equips them for the various trials of nature. Individuals that survive this developmental stage live to reproduce. Those that fail to attain the proper physical and psychological development will be picked off by predation and other pitfalls of nature.

Much as we try, the captive environment can never be identical to the natural state. The infinite possibility of external stimuli available to the wild animals is simply not available to the captive population. Moreover, for captive situations, the human factor involved is too overwhelming. Hence, in captive situations, we employ various forms of environmental and behavioral enrichment devices to mimic the wild situation in the hope that the captive population can be allowed to attain their full potential.

The Need for Welfare and Enrichment

The single most important difference that separates the modern zoos from the ancient menageries is the fact that animals are no longer treated as a display item kept solely for the enjoyment of the public.

The modern zoo must take on the role of the educator. The majority of the city dwellers do not have the opportunity to came close to nature, let alone wildlife. Not everybody can go on an African Safari, or a jungle trek, and as a result, they have become so far removed from things natural and wild, that they have forgotten how pretty the natural world can be. They no longer understand the dynamics of a natural ecosystem, and because of this lack of understanding, they do not see the need to preserve nature and are generally not concern with the conservation of nature.

Most Zoological Gardens are easily accessible to the public. When we admit the public into our premises, we have an opportunity to educate them. Through the use of signatures and guide books, we are able to make them more aware of the animals in our collection and their natural habitat. However, the best form of education is by the use of visual images. And there are no better image than a wild animal in a natural setting, behaving in a manner befitting of its species. A single lioness kept in a barren cage does nothing to educate except to allow our visitors a sense of what the lioness look like. If that same lioness is now kept in a social group, on display in an exhibit that represents its wild habitat, it will behave in a manner that is closer to its wild counterparts. In such an exhibit, we not only show our visitors the physical appearance of the lion, we also present to them the natural behavior of these animals. By taking the lioness out of the barren cage, we can also promote the need to conserve the habitats of these animals. For if the animal is kept in a barren cage and seems to be surviving healthily, wherefore lies the need to preserve their natural habitat?

The Zoological Gardens has also much to offer in the scientific field. Scientist spend years or even decades studying animals in the wild, wasting a massive amount of time looking for their study subjects. Most of the behavior of these animals are not even visible to the observer even if the subject is observed 24 hours a day, 7 days a week.

The Zoo, however, have a most important criteria to offer these scientist. Our animals are always here. Granted captive behavior is not representative of the full repertoire of behaviors available to the wild animals, but observed captive behavior can be used as a supplement to the wild behavior observed. The combination of the two will boost our understanding of these animals tremendously.

For this purpose, we need to encourage our animals to behave as naturally as possible. A polar bear pacing around its barren enclosure is exhibiting stereotypic behavior that is not observed in the wild, and as such, does not enhance our understanding of their natural behavior.

With the introduction of proper enrichment devices, we can encourage the animal to behave more naturally, hence increasing their value in the scientific field.

At the rate at which our natural environment is being destroyed to make way for development, the Zoological Parks around the world have an increasingly important role to play. That of the collection center for wildlife for the purpose of preserving their genes for eventual reintroduction.

Animals that are born and bred in captivity will behave differently from their wild cousins. They do not experience the same dynamic environment. In a captive situation, food is provided on a platter, and mates are readily available. Moreover, there are no problems with predation or diseases. Captive animals live a life of luxury, which will eventually affect their ability to survive in the wild. If these are the type of animals that we are preparing to reintroduce into the wild, we may as well drop the project now as they will definitely not survive.

The use of enrichment devices that tax the ability of the animals in captivity will serve the purpose of "training" them for their eventual reintroduction. The trained animal may not be the same specimen that will be released, but by preserving its wild behavior, we allow its progeny to retain some of that instinct too.

Environmental Enrichment Devices

Environmental Enrichment Devices can be used to accomplish numerous task. In the Singapore Zoological Gardens, we seek to achieve the following with our devices:

·         To increase the behavioral repertoire of our captive population,

·         To reduce abnormal behavior characteristic of wild animals in captivity,

·         Encourage positive utilization of the whole enclosure space (both horizontal and vertical),

·         Enhance the ability to cope with novelty, and

·         Prepare the animal for eventual re-introduction programs.

Increasing Behavioral Repertoire

Solitary animals kept in a barren enclosure have little opportunity for the display of behavior. By including in the exhibit space climbing structure for arboreal primates, thick trunks as scratching poles for our big cats, sand pits for our burrowing meerkats or a mud wallow for our rhinoceros, we encourage these animals to use these furniture to exhibit their natural behavior.

The interaction between con-specifics can also be used as an enrichment device. Animals that occurs in social group will have a whole repertoire of behavior that comes with being in a group, and this should be encouraged whenever possible.

Reduction of Abnormal Behaviors

With the increase in the repertoire of natural behavior, abnormal behavior will naturally decrease.

Stereotypic behavior and other such undesirable behaviors are usually caused by frustration. The animal has an internal drive that is motivating its action. However, in a captive situation, there may be a missing link in the sequence of this motivated behavior. Because of this, the animal cannot carry out the sequence in its entirety, thus resulting in the repetition of the broken behavior. If this situation is allowed to persist, the mental state of the animal may deteriorate to such an extend that it becomes irreversible.

By the use of proper enrichment devices, the animal’s behavior can be directed. A good enrichment device will supply the motivating factor necessary for an action, and it will also be able to supply a reward for the behavior. The reward will serve as the target in this case, and tell the animal that the sequence has ended, and the animal can then move on to another behavior, thus reducing the possibility of stereotypy.

An example of such a device is the classic "food in ice" scenario. Bits of food items are frozen in an ice block, and presented to some otters. The motivating factor here is the food, and the barrier, the ice. In order to get to the food, the otters have to device a way to break the ice. The amount of time spend on the device depends on the number of otters working on it, and the size of the ice block. The termination of the behavior comes when all the food has been extracted and eaten. The device is relatively easy to make, but it will take the otters quite a while before they manage to get to the food items, thus making this an ideal tool for not just the otters but other animals as well.

Positive Utilization of Enclosure Space

The enclosure space can be divided into vertical space and horizontal space. Flightless animals are only capable of utilizing the horizontal space unless the vertical space is filled with climbing or swinging structures. By the installation of a climbing gym in a monkey’s cage, we can increase the usable space of the exhibit by at least two fold, if not more.

Ability to Cope with Novelty

Animals born and bred in captivity have little chance of meeting new animals or objects. If the enclosure furniture is never changed, the animal will soon learn all that there is to learn about its limited living space. As result, it becomes too comfortable in its enclosure, and looses its curiosity. Such an animal will be afraid of items that it is not familiar and it will not be interested in exploring a new environment.

Such an animal will loose its display value as all it is interested in, is to hide from the public and try not to be seen. An ideal display animal is one that can be readily seen, and has such a wide repertoire of behavior such that every time one looks at it, it is doing something different.

The ability of an animal to cope with novelty objects can be trained. All that need to be done is the introduction of new furniture or toys on an irregular basis. Once the animal gets used to the changing environment, it will learn to cope with the novelties by examining it to determine whether it is safe or whether it will cause harm. This creates a minor stress factor in the life of the animal, which, if managed properly can be of immense benefit to the animal’s well-being. Though too much stress is detrimental to the health of the animal, an entirely stress free life will produce an animal that is ill suited to living in the wild.

Eventual Reintroduction of captive Population

With the rate of extinction of wild flora and fauna, there may come a time when the only way to restore the natural biodiversity is through well organized reintroduction programs. On that day, zoos and other holding facilities around the world will have to supply the necessary candidates for reintroduction.

Captive bred animals are notorious in their inability to survive in the wild. Take a simple bird, like the canary. Once out of a cage, its chances of finding food or to evade predation is almost nil. This is such because the pet trade has been able to breed and supply domesticated canaries to the public. The survival instinct has been bred out of these birds since they have no need to fend for themselves in a captive environment.

Animals in the zoo may still retain some of their survival instinct. This is true because they have not been in the zoo for more than a few generations. After a few hundred years in captivity, even a tiger will loose its ability to hunt in the wild if proper provisions were not made to allow it to develop its musculature to its full extend. It is a well known fact that predators’ behavior are highly plastic. That is to say, experience is more important than instinct. Tiger cubs usually stay with the female for at least a year or two before they are required to leave the mother and begin fending for themselves. During this time, they are trained in the various hunting techniques and survival skills. It is also during this time that they are introduced to the various prey items that they will be hunting.