Zoos and animal welfare

Andrew Tribe,

^{School of Animal Studies,
University of Queensland,
Gatton Qld 4343,
Australia.
Email a.tribe@.uq.edu.au}

• Zoos and the animal welfare debate
• The effects of captivity on behaviour
• Assessing the welfare of captive animals
• Environmental enrichment
• The future
  
  
• References
  
  

Despite their popularity and place in our tourism history, in recent years zoos have undergone considerable change in both their structure and function. Whilst remaining attractive places to visit, zoos now seek a new image – one that emphasizes their role in conservation and public education. However, changes in public expectations and the zoo’s own objectives mean that today there is far more scrutiny of the way in which their animals are managed and utilised.

Zoos and the animal welfare debate

The history of zoos as menageries of animals in cramped conditions and maintained largely for human amusement has left a lasting impression on some people of poor animal welfare. As Stevens and McAlister (2003, p. 97) explain: ‘It is quite apparent that, for the most part until fairly recent times, the way in which wild animals were kept is something of which humankind should be embarrassed and ashamed.’

Thus, despite improvements in their captive animal management and adoption of conservation objectives, zoos are still seen by some as being superficial, expensive, unnecessary and therefore indefensible. For instance, the Australian and New Zealand Federation of Animal Societies is opposed to keeping wild animals in captivity (ANZFAS, 1996). Similarly, the Born Free Foundation (BFF) continues to campaign strongly in the UK and Europe for the abolition of ‘the confinement of wild animals for human entertainment’, while in the U.S., organisations such as the Society for the Prevention of
Cruelty to Animals (SPCA) and People for the Ethical Treatment of Animals (PETA) provide a consistent voice for the anti-zoo lobby.

In addition, according to Hutchins and Smith (2003) there is likely to be a continued growth in animal welfare and rights organizations, as well as concern by the public for the welfare of animals in captivity.

In July 1994, the World Society for the Protection of Animals (WPSA) and the BFF issued The Zoo Inquiry (WPSA, 1994). Although critical of zoos, this document was significant in that it also made some constructive recommendations regarding animal welfare standards, and the role of zoos in conservation.

In the years since this report, many of its recommendations have actually been adopted by the zoo industry, at least in developed countries. This has come about through a combination of three factors: zoo legislation and codes of practice, the development of captive animal exhibits, and improvements in husbandry and veterinary care.

Zoo Legislation

Zoo Legislation now exists in most countries around the world (Cooper, 2003). Although their content varies, there are some basic provisions that are common to all, including aspects of animal accommodation and facilities; special needs of particular species; animal welfare and nutrition; veterinary attention and facilities; hygiene; emergency procedures; staff safety; training and facilities (Macdonald and Charlton, 2000).

Codes of Practice

Codes of Practice represent a form of industry self-regulation and have been developed over the past decade by a number of regional zoo associations to try to raise the standards of animal welfare in their member institutions. In some regions these codes are enforced by the terms of membership of the association itself, with expulsion as the penalty for non-compliance, while in others they are only morally enforced using self-regulation. More recently, these codes have been supplemented by a Code of Ethics developed by the World Association of Zoos and Aquaria (WAZA, 1999).

The Development of Captive Animal Exhibits

The Development of Captive Animal Exhibits over the past 200 years can best be understood by reference to first, second and third generation exhibits (Shettel-Neuber, 1988). The label first generation refers to the barred cages used in the 18th and 19th centuries to display exotic animal species, which were designed primarily to display the animals in isolation to the visiting public. In the 20th century these were replaced with larger, more open cement enclosures often surrounded by moats – the second generation of exhibits. However, over time a rising concern over animal welfare meant that they were no longer acceptable (Shettel-Neuber, 1988; Kirkwood, 2003). From the middle of the 20th century many zoos developed more naturalistic enclosures that sought to replicate animals’ natural habitats. These third generation exhibits provided more space and typically used more vegetation (Shettel-Neuber, 1988).

In the 21st century, exhibit design continues to develop as zoos seek to better fulfil their objectives. The latest generation of exhibits combines technology, new construction techniques and a variety of additional interpretive media to create what has been referred to as an immersion experience. Unfortunately, there are still zoos in the world which have failed to improve, and where the standards of animal welfare remain low (Knowles, 2003). The continued existence of such institutions illustrates both the diverse nature of the zoo industry, and the continual battle to balance public expectations with commercial reality.

Improvements in Husbandry and Veterinary Care

Improvements in Husbandry and Veterinary Care have similarly been dramatic over the last half century, and have included advances in nutrition, chemical restraint, knowledge of infectious and non-infectious diseases and their treatment and prevention, linked with a marked growth in research into aspects of captive animal biology, husbandry and medicine. The result is that most wild animals now live longer in captivity than they would in the wild (Kirkwood, 2003).

However, discussion over the welfare of zoo animals continues and, as Moran (1987, p. 2) explains: “no amount of data or enhanced environments will objectively settle the debate over the ethics of zoological institutions”. This debate has been seen in the recent controversy over the importation of elephants to Melbourne and Taronga Zoos. Despite spending tens of millions of dollars to create the latest elephant enclosures, these institutions have faced continual criticism for a number of animal welfare concerns. Lack of space and the absence of natural foraging behaviour are the most serious, but inadequate social groupings and diets have also been mentioned (Phillips, 2005).

However, it is not easy to know what animals need and want and whether what they want is good for them (Kirkwood, 2003). This remains the real quandary for zoos today – to provide their animals with social and physical environments that confer upon them a high level of welfare within the confines of limited space and financial resources. It requires an understanding of the effects of captivity on behaviour, and from this an appreciation of how enclosures and husbandry practices can be manipulated to improve the welfare of their captive animals.

The effects of captivity on behaviour

Captive enclosures are, by their very nature, likely to be more simplistic than natural habitats, and this has both advantages and disadvantages for the exhibited animals. On the one hand, food is in plentiful supply, travel distances are small, health is closely monitored, mates are often provided and there are no predators. However, captive animals are also often faced with the problem of how to fill large amounts of time with the limited number of appropriate behaviours allowed by the enclosure (Shepherdson, 2003). Captive conditions, being more restrictive and less diversified than the wild, may offer the animal little opportunity for behavioural control and so are likely to exert some significant effects on their behaviour.

Most of the effects that captivity exerts on behaviour occur in the short term to the individual as it grows up under the specific conditions of its confinement (Carlstead), 1996). The most obvious of these is the development of abnormal behaviours, and many studies have described abnormal behaviours that appeared to be induced by captive environments (for instance Kiley-Worthington, 1990; Mason, 1991; Robinson, 1998). These behavioural abnormalities can include:

Stereotypies – behaviours that are fixed, apparently purposeless and repeated, such as weaving, rocking and pacing.

Increased aggression – to both social partners and other animals.

Altered time budgets – where the distribution of time between behaviours is very different from in the wild.

Increased frustration or conflict behaviour – including displacement behaviours or behaviours that seem out of context such as head-shaking, scratching, chewing or licking.

Increased fearful behaviour – including avoidance, shivering, sweating or over-reaction to slight environmental changes.

Ontogenic behavioural changes – where an animal no longer performs the normal behaviour for its species at that age or stage of development.

The development and expression of any of these behaviours may be an indication of distress and hence of a lowered level of welfare (Kiley-Worthington, 1990). However, the degree to which abnormal behaviours can be used as a measure of animal welfare is still a controversial issue (Shepherdson, 1999). They may be an indication that the captive environment is somehow inappropriate for that animal, but their expression may actually be of benefit to the animal in that situation. Consequently, accurately assessing the welfare of animals in captivity is still open to dispute, as the recent debate over the importation of elephants to Taronga and Melbourne Zoos has shown.

Assessing the welfare of captive animals

In practice, the welfare of captive animals is probably better inferred from a multi-disciplinary approach which includes an assessment of an animal’s health, physiology, behaviour and knowledge of its wild lifestyle (Shepherdson, 1999). These types of studies have demonstrated a link between captive behaviour and physiological indicators. For instance, housing conditions have been found to significantly influence physiological measures of stress in primates, in particular immune competence and reproduction (Shepherdson and Carlstead, 2000).

Such research also highlights the requirement for captive environments to meet the behavioural needs of their animals. The evidence for behavioural needs has been reviewed by Hughes and Duncan (1989), and they conclude that thwarting a strong motivation may over time result in frustration which can be a cause of suffering and reduce welfare. Research into various fields of zoo biology has helped to clarify what the captive environments of particular species should and should not include, but much more work remains to be done (Robinson, 1998).

Another, more general, potential cost of keeping animals in inappropriate enclosures has been outlined by Carlstead (1996): animals that do not exhibit a wide range of normal behaviours give the impression to the visitors of being bored and unhappy in their confinement. In these circumstances, visitors may fail to understand the zoo’s educational information and its underlying message of conservation. Consequently, he argues that it becomes all the more important for zoos to develop their animals’ exhibits as miniature examples of the wild habitats in which animals are encouraged to display their full range of natural behaviours. The husbandry and design techniques used to achieve this are referred to as environmental enrichment.

Environmental enrichment

Environmental enrichment has been defined as an animal husbandry principle that seeks to enhance the quality of captive animal care by identifying and providing the environmental stimuli necessary for optimal psychological and physiological well-being (Shepherdson, 1998). In practice, this means providing a complex and diverse environment that increases the possibility that the captive animal’s own behaviour will produce what it needs: finding food, demarcating territory, nest building, escaping conspecifics or hiding (Carlstead, 1996).

The most obvious and straightforward method of achieving this would seem to be to increase the space available to the animals: inadequate cage size has been linked to the development of a number of abnormal behaviours (Shepherdson, 1999). However, many authors have also pointed out that both in the wild and in captivity, the amount of space that an animal uses is determined by the resources available (food, water, nesting sites, mates) and not by a specific requirement for a given amount of space (Maple and Perkins, 1996). In other words it is the quality rather than the quantity of space that is important, and this is what effective environmental enrichment seeks to provide.

There are essentially four forms of environmental enrichment that can be incorporated into captive animal husbandry: physical, social, feeding and conditioning.

Physical Enrichment

Physical Enrichment can include providing structures that increase the surface area over which an animal can move, objects and toys that maybe manipulated or novel items that visually stimulate animals such as bright colours, lights, moving objects, mirrors and even non -toxic soap bubbles. It can create opportunities for the performance of species specific activities and allow a degree of choice and control over daily activities.

Social Enrichment

Social Enrichment can be in the form of increased group size, or mixed (intra specific) species exhibits in compatible groups. This method of enrichment is believed to be effective in providing complex, dynamic and long term benefits to captive wildlife as social partners allow an individual to interact with its surroundings to a much greater degree than if it were alone (Carlstead, 1996).

Feeding Enrichment

Feeding Enrichment is the most commonly used form of enrichment especially when targeting carnivore species. Many wild animals spend most of their active hours feeding and foraging, while captive animals on the other hand receive food frequently and often as a single daily serve (Maple and Perkins, 1996). Such feeding routines reduce foraging, and in combination with the missing stimulus to hunt or forage, can contribute to the development of stereotypic behaviours. However, feeding enrichment strategies can be implemented which can include scattering or hiding the feed through the exhibit, or hanging feeder tubes which drop small food items at random into the enclosure.

Conditioning

Conditioning is a form of enrichment which promotes close keeper-animal interactions through implementing training exercises to facilitate certain husbandry routines (Embury, 1993, Shepherdson, 2003). Successful conditioning programs enable greater control over animals, allowing for more flexibility in the husbandry regimes while also providing the animals with cognitive enrichment (Shepherdson, 1999). Conditioning is now frequently used for many species, and is the basis of the ‘free contact’ system of elephant management employed at Taronga and Melbourne Zoos.

Although its benefits have been recognised for many years, it is only over the last decade that environmental enrichment has been seen as an integral part of captive wildlife management. However, the degree to which new strategies are incorporated into captive animal management is often low and the value of many of these strategies remains at best undetermined. The reason for this is that zoos usually only consider environmental enrichment after other husbandry tasks have been completed, with little formal quantitative evaluation (Hoy et al, 2008a, b). If zoos are to continue to develop and improve captive enclosure design and husbandry, this is a weakness that needs to be addressed.

The future

As Carlstead (1996) concludes, it is possible to provide adequate captive environments for wild animals if their specific needs are understood and accounted for when designing exhibits and husbandry procedures. Recent research and developments in zoo nutrition, chemical restraint, captive animal biology, husbandry and medicine have all contributed greatly to this process, and together with a better knowledge of their behaviour, zoos are now far better equipped to create enclosures and husbandry systems that are likely to provide for their animals’ welfare.

The difficulty, of course, comes in evaluating different zoo enclosures and husbandry systems, and in understanding those features of the captive environment which need to be improved. Recently, however, research has been conducted with captive great apes (Fernie, 2008) and elephants (Gurusamy, 2008) which have developed a procedure for doing this. This has involved the creation of welfare sensitive indices which use expert stakeholder opinions to rank various aspects of husbandry and then correlate them with the behaviour of the captive animals. These indices can then be used to rank enclosures in different zoos and to highlight those aspects requiring most improvement. Thus they can be used in zoos across the world, and can act as models for the creation of welfare indices for other captive species.

However, more still needs to be done. In particular, further research is essential into the behavioural needs of different species and how these can be met in captivity (Kirkwood, 2003). In addition, environmental enrichment should be given a higher priority so that it can be incorporated into exhibit design and husbandry programmes in the same way as nutrition and veterinary care (Shepherdson and Carlstead, 2000). This may require investment in the development of ‘artificial’ enrichment techniques such as automated husbandry systems to provide effective enrichment without requiring greater staff input (Hoy, 2008b).
As the threats to wild animals continue to grow and their populations in the wild become more threatened, it is likely that the role of zoos will become even more important. However, if this role is to be fully recognized it is essential that zoos take all steps to minimize the welfare costs to their animals. Otherwise, they risk becoming continually sidetracked in the captive animal welfare debate and in defending their very existence.

References

ANZFAS 1996, Policy Compendium. Australian and New Zealand Federation of Animal Societies Inc., Collingwood, Vic.

Carlstead, K. 1996, Effects of captivity on the behaviour of wild mammals. In: “Wild Mammals in Captivity”, pp 317 – 333. Eds. Kleiman D.G., Allen M.A.,
Thompson K.V. and Lumpkin S, University of Chicago Press, Chicago.

Cooper, M. E. 2003, Zoo legislation. International Zoo Yearbook 38: 81-93.

Embury A.S. ( 1993) Environmental Enrichment, in First Conference on environmental Enrichment, Metro Washington Zoo, July 1993, Portland, Oregon, USA, pp 1 – 9.

Fernie, A. (2008) The Creation and Implementation of a Great Ape Welfare Index. PhD Thesis, School of Animal Studies, University of Queensland, St. Lucia.

Gurusamy, V. (2008) Non-invasive endocrine monitoring and behavioural analysis to measure stress and welfare in captive elephants. Unpublished PhD research, School of Veterinary Science, University of Queensland, St. Lucia.

Hoy, J., Murray, P. and Tribe, A. 2008a, Limitations of current enrichment practices for captive mammals. Appl. Anim. Behav, (accepted for publication).

Hoy, J., Murray, P. and Tribe, A. 2008b, Limitations involved with evaluating enrichment for captive mammals. Appl. Anim. Behav, (accepted for publication).

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Hutchins, M. and Smith, 2003, Characteristics of a world-class zoo or aquarium in the 21st century. International Zoo Yearbook, 38: 130-141.

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Kiley-Worthington, M. 1990, “Animals in Circuses and Zoos: Chiron’s World?” Little Eco-Farms Publishing, Essex.

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Maple T.L. and Perkins L.A (1996) Enclosure Furnishing and Structural Environmental Enrichment. In “Wild Mammals in Captivity Principles and
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Phillips, C. 2005, Elephants in crisis. CAWE Update, July 2005, p.2.

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Shepherdson, D. J. and Carlstead, K. 2000, When did you last forget to feed your tiger? Raising the bar on environmental enrichment in AZA zoos and aquaria. AZA Annual Conference Proceedings 2000, pp 231 – 235.

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World Society for the Protection of Animals (WSPA) 1994, The Zoo Inquiry. World Society for the Protection of Animals, Oxford.