Legislation regarding zoo management
In 1999, the EC Zoos Directive was a major step forward in European legislation concerning zoos and resulted in the closure of some very poor zoos. It set out requirements for licensing and inspection, proper record keeping, standards of animal care and requirements for education and conservation. It states that zoos not directly involved in captive breeding or reintroduction programmes should be involved at least with supporting research and training. The UK’s Zoo Licensing Act 1981 is also very involved with the management of zoos.
The Secretary of State’s Standards of Modern Zoo Practice (SSSMZP) is a guideline of expected standards for zoos and has five main principles which are based on the five freedoms:
1. Provision of food and water à regards health and hygiene aspects as well as appropriateness of the quality, quantity and variety of food provided, taking into account species, sex, age, reproductive condition etc.
2. Provision of a suitable environment à includes physical features of the environment and appropriateness for the species and minimizing the possibility of escape. Also includes health and safety considerations (electrical equipment, broken barriers etc) and hygiene (cage cleaning and waste disposal etc).
3. Provision of health care à Provision of veterinary care and disease prevention.
4. Provision of opportunity to express most normal behaviours à physical and social environments that promote behaviour similar to that seen in wild animals.
5. Provision of protection from fear and distress à appropriate environments and the ability from avoid human contact.
There are a number of other organisations that help the law govern zoos and provide guidelines and advice. There include the British and Irish Association of Zoos and Aquariums (BIAZA), the European Association of Zoos and Aquiariums (EAZA), the Association of Zoos and Aquariums (AZA) in North America, the Australasian Regional Association of Zoos and Aquariums (ARAZA), the Association of British Wild Animal Keepers (ABWAK) and DEFRA (Hosey et al. 2009).
Behaviour
Animals, including carnivores, have been kept in captivity since pre-historic times, and there are many principles to consider when housing carnivores so that the management is beneficial and influences natural behaviours and removes factors that have adverse effects. These principles include taking into account the animal’s natural territory and habitat, sleeping patterns, diet and foraging patterns and social structure (Blackshaw, 1986). Poor management and housing can lead to the animals showing abnormal behaviours, known as stereotypic behaviours, which are repetitive and apparently functionless. These include activities such as pacing, excessive licking and sometimes self-mutilation. High levels of stereotypy can indicate poor welfare (Kleiman et al., 2010).
The extent to which animals can show species-typical behaviours depends on the opportunities provided by their environment, i.e. prey catching behaviour may not be possible in most zoo environments. Behavioural diversity is a good measure of how closely the zoo environment allows the animals to perform species-specific behaviours. The significance of learning is that it permits the animal to detect patterns and relationships between objects and events in their environment. If an animal is prevented from performing a natural behaviour it is motivated to do, it can lead to frustration, and over long periods can lead to adverse effects on welfare (Hosey et al 2009).
Preventing natural behaviours in captive animals can lead to stress and frustration and impair the development of certain regions of the brain involved in behavioural sequencing. This limits the animal’s ability to behave appropriately and natural, therefore inducing stereotypical behaviours. Stereotypy is more commonly observed in naturally wider-ranging species such as polar bears (a typical polar bear enclosure is one-millionth the size of its minimum natural home range) (Clubb & Mason, 2003).
Stereotypic behaviours represent a divergence from the behaviour of wild animals and can indicate Central Nervous System problems, which affects the animal’s suitability for re-introduction (Mason et al., 2007).
Stereotypic behaviours can be present due to a number of factors. In the fennec fox (Vulpes zerola) abnormal behaviours increase with visitor numbers, in leopard cats (Felis bengalensis) when housed near predators and/or without hiding places and in leopards (Panthera pardus) when kept in holding pens and in many other carnivorous species, abnormal behaviours increase on ‘starve days’ (days when the animals are not fed). There are a number of methods used to try and reduce and prevent the occurrence of stereotypical behaviours (from Mason et al., 2007):
1. Genetic selection – abnormal behaviours are selected against. It is national policy in the Netherlands to select against abnormal behaviours on mink ranches. Zoos occasionally do similar but indirectly, by not breed from animals showing high levels of stereotypical behaviour. It is not often used in zoos and is inappropriate for animals that have the potential for release. It also does not tackle the underlying cause of the behaviour.
2. Pharmacological compounds – serotonin-reuptake inhibitors (‘Prozac’) is widely used in companion animals and has been used in captive bears and primates and has previously successfully reduced stereotypic behaviours in a polar bear who had been pacing and fur plucking for 20 years, but it is not always successful and again, does not tackle the underlying cause of the behaviours.
3. Positive reinforcement of other behaviour – alternative behaviours reinforced with reward has been successful in some zoo cases. It was used to improve captive dolphin welfare and stop the animal from repetitively regurgitating after a meal. The dolphin was rewarded for not regurgitating its food. This method proved successful but is very labour intensive and does not deal with the original cause of the behaviour.
4. Physical prevention or punishment – using objects to obstruct the usual pacing pathways of an animal, or using unpleasant tastes to discourage repetitive licking of objects in the enclosure. Can be successful but does not tackle the underlying problems.
5. Environmental enrichment – using novelty objects to change the everyday environment of the animal, and change their daily routine. This gives the animals the opportunity to perform natural behaviours and they can choose whether to interact with the object. Enrichment can also include altering the physical environment within the enclosure or altering the normal feeding regime. This tackles the root problem causing stereotypical behaviour is most commonly used.
It has been shown through previous studies that stereotypical behaviours are predicted by
natural ranging behaviour (home range size and travel distance) more so than foraging behaviour (e.g. hunting). Wider-ranging natural lifestyles also predict high infant mortality. Enclosures and enrichment focussing more on ranging behaviours (e.g. more dens, more space, more variability) may prove more effective in preventing and reducing stereotypical behaviour and improving welfare (Clubb & Mason, 2007).
Feeding
There are a few ways of feeding captive carnivores and different types of food they can be fed, such as whole carcasses, feeding prepared meat and soft-textured feeding. Feeding a whole carcass often requires additional supplementation as the animal will often selectively eat certain parts of the carcass, resulting in an inadequate diet. There is also an issue with the zoo being able to maintain a sustainable supply of whole carcasses. In many societies, the feeding of whole carcasses is disliked by the viewing public (Young, 1997).
Prepared meat if often used as is usually skinned muscle from livestock, and is also nutritionally inadequate so requires supplementation. A problem with this feed type is reduced sensory input. In the wild, a carnivore uses its senses for food identification. They lean over the prey and use their whickers to feel the direction of the fur or feathers as they often have a set method for dissecting their prey. Whiskers also have mechano-receptors which links to the canines suggesting that the teeth can ‘feel’ their way to the killing bite. Young carnivores learn what is appropriate by observing what the mother brings back after a hunt. For successful re-introduction of captive animals they need experience in identifying appropriate prey species and utilizing the carcass (Young, 1997).
Management programmes have shown that appetites and body condition improve if the animals are fasted for 1 or 2 days a week (known as starve days). Either no food is fed or a large bone is provided. This simulates the feeding of most carnivores in the wild as they will not successfully hunt every day. Feeding bones has an additional function in promoting dental health and natural behaviour and therefore provides enrichment (Tilson et al. 1994).
Diet quantities should be increased by 10-20% in animals housed outdoors during the winter and decreased in the summer and increased to ad lib during lactation. Commercially prepared diets (also known as soft-textured) are commonly fed, however recent studies show an excess of vitamin A and phytoestrogens, and some deficiencies in taurine but manufacturers are now correcting the health problems. No other supplements should be necessary with a properly formulated diet (Tilson et al 1994).
Regulation 26.3(a) of the Animal By-Products Regulations 2005 states that zoos require authorisation from their local Animal Health Office before they can feed animal by-products to other animals on their premises (Hosey et al 2009).
Timing of feeding can influence behaviour if its predictability allows the animals to anticipate it, which can lead to an increase in aggression or stereotypic pacing. Captive feeding routine may also differ from the natural activity of the wild animals. For example, a lot of carnivores, such as lions, generally hunt at night as they have good night vision and their prey is at a disadvantage.
Behaviour can also be strongly influenced by the way food is presented. Multiple feedings of hidden food for leopard cats (Felis bengalensis) results in a decrease in pacing but an increase in locomotory/exploratory behaviour (Hosey et al. 2009).
Environment and Housing
An important variable in the environment is space. Generally, zoo enclosures are smaller than the animal’s natural home range, especially carnivores which generally have a large home range to find food. Restricted space is a causal factor in the promotion of stereotypy development. Different animals are affected differently by their captive environment, for example, wolves (Canis lupus) spend more time at rest in larger enclosures but behavioural diversity appears to be more related to group composition than enclosure size.
Different species use different parts of their enclosure in different ways and some areas more frequently than others. Cats mostly show stereotypical pacing at enclosure edges which is an artificial territory boundary and they can see visitors and keepers approaching. Chimpanzees prefer more elevated parts of the enclosure whereas gorillas prefer to stay on the ground (Hosey et al 2009).
General consensus is that space is less important than the quality of the space within the environment in regards to structural complexity. Many zoos have moved towards having more naturalistic enclosures which simulate the natural habitat of the animal. With this comes an increase in complexity and size and is accompanied by more naturalistic behaviours (Hosey et al. 2009).
At the very least housing should ensure that the five freedoms are fulfilled. Very little is known about the exact requirements of many species so past experience and knowledge is used to meet the animals basic needs.
It is also important to keep animals within the right social structure. With the exception of lions, all felids are generally solitary but in zoos are often kept in pairs or trios. Studies have shown that smaller cats housed in groups of greater than two were less likely to reproduce than those kept in pairs and spend more time pacing. It has been suggested that felids of this type should be housed singly and introductions of males and females made for breeding purposes or enrichment. It has been reported that there is a positive relationship between enclosure size and successful reproduction (Mellen & Wildt, 1998).
Enrichment
Enrichment is any change to an animal’s environment or routine that is implemented to improve health and physical and mental well-being and aims to generate a behavioural change in the animal and prevent or reduce stereotypies (Hosey et al. 2009).
There are different types of enrichment:
Food-based enrichment: centred on food i.e. new presentation or types of food.
Physical enrichment: change to the structural environment or the provision of objects for manipulation.
Sensory enrichment: anything that stimulates the animals senses i.e. blood trails.
Social enrichment: interactions with other animals or people.
Cognitive enrichment: additions to the environment that require problem solving etc for mental stimulation (Hosey et al. 2009).
Many experiments have been done on the effects of enrichment on carnivore behaviour. One experiment was conducted on cheetahs that were regularly seen to be pacing. Temporal feeding (time of feed) and spatial feeding (location of food) were altered and olfactory enrichment was provided in the form of fresh ungulate dung. This increased variation did prove to reducing the pacing behaviour of the cheetahs (Quirke & O’Riordan, 2011).
A study on captive coyotes showed that making the feeing regime unpredictable increased the frequency of natural behaviours such as marking and howling. Varying the feeding time between predictable and unpredictable can be beneficial in promoting varying behaviours (Gilbert-Norton et al. 2009).
Foraging behaviour is an essential part of an animal’s survival so enrichment to stimulate foraging could be crucial. Previous work on this includes artificial moving prey to encourage natural hunting in servals (Felis serval) and cheetahs (Acinonyx jubatus). In European wild cats (Felis s. Sylvestris) electronic feeders promoted natural hunting and prevented behavioural problems. In tigers (Panthera leo) stereotypic behaviour was decreased by manipulable feeders. Hiding food around the enclosure reduced stereotypies in black bears (Ursus americanus) and increased searching behaviour in bush dogs (Speothos venaticus) (Kistler et al. 2009).
An experiment was done on red foxes (Vulpes vulpes) which involved 3 methods of enrichment using electronic feeders combined with: a self-service food box, allowing control over food; manually scattering food unpredictably; and an electronic dispenser delivering food unpredictably. The aim was to stimulate searching behaviour. The diversity of behaviour and overall activity was increased, especially when the foxes had control over their food. Manual scattering and the electronic dispenser enhanced food searching behaviour indicating that foraging behaviour can be stimulated when food is delivered unpredictably (Kistler et al. 2009).
Hiding spaces are important for clouded leopards (Neofelis nebulosa) and providing them with areas such as caves or dense areas of foliage so they can hide from view from the public can reduce stereotypical behaviours and make the animals more comfortable. Forms of sensory enrichment can include leaving piles of ungulate dung and blood in exhibits and playing the sounds of other animals into the exhibits. Social enrichment in carnivores can be difficult as they are often territorial and can be aggressive towards intruders in their territory (Hosey et al 2009).
In regards to social enrichment, it has been suggested to rotate members of a pair on exhibit daily i.e. have the male on exhibit in the morning and the female in the afternoon. This way the animals can explore the exhibits and any scent marks the other individual left behind. This has been shown to increase the activity of Siberian tigers (Mellen & Wildt, 1998).
Breeding and conservation
Reproduction and mating strategies are very different between species and there are many factors that can influence reproductive success. A behaviourally competent animal could be expected to show courtship behaviours in the right situation, such as when paired with a member of the opposite sex of the same species, as well as show the appropriate behaviours after birth such as good parenting behaviours, but animals in captivity sometimes don’t show these behaviours. It is also important to monitor the reproductive status of animals to know when to bring animals together for mating and when to make changes to the animal’s environment. Sometimes it is necessary for zoos to interfere with the rearing process, such as when a mother abandons her young (Hosey et al. 2009).
Captive breeding and re-introduction projects are fundamental in the conservation of species, however only one-in-three captive-born carnivores survive in the wild. The animals in captivity do not have the natural behaviours needed for survival in the wild as they have a lack of hunting skills and little fear of humans. They are usually killed due to hunting, collisions with vehicles, starvation, disease or lack of social interactions such as pack formation and group hunting (University of Exeter, 2008). There is a lot of focus on carnivores as a flagship species for conservation societies, as they have visual appeal.
Carnivores are long-lived, have extensive social learning and relatively long generations which can mean populations struggle to recover after significant decline. A number of reviews on carnivore conservation have proposed that in-situ conservation (habitat protection/restoration, prey densities) may be more effective than releases back into the wild (Jule et al. 2008).
It has been shown statistically that release projects are more likely to succeed when wild-caught animals are used. The most common cause of death for wild caught and captive-bred animals is by human means (hunting, poisoning, collisions with cars etc.) Often the initial conflict with humans is not resolved by the time the animals are released. Also, starvation, inter-species aggression (such as lions killing smaller carnivore’s e.g. wild dogs) and disease (e.g. rabies and distemper) were most common in captive-bred animals. This shows that captivity negatively influences the chances of survival of the animals because they lack the necessary skills to hunt and socialise, they are more adapted to human contact and lack the immunity of wild individuals. Wide-ranging carnivore’s poor response to captivity results in reduced breeding success and high stereotypy which can also affect reintroduction success (Jule et al. 2008).
It is also important to consider the aspects of social behaviour prior to release. A founder group composition is likely to determine success whereas persistence will depend on the formation of new groups to maintain reproductive capacity. Keeping animals in their original groups can also reduce stress. Using a pre-release enclosure has been shown to increase re-introduction success (known as ‘soft-release’). Animals familiarise themselves with the release area (Hayward & Somers, 2009).
Conclusion
In conclusion, given all the information that I have presented, I believe that modern zoos are doing very well in better understanding the needs of carnivores in captivity and are changing their management accordingly. Obviously if enclosures could be much bigger in accordance with natural territory size, that would be a benefit, however there are obvious restraints for this. I think zoos have done well in finding alternatives for this and stereotypical behaviours, such as environmental and feeding enrichment and are working well to maintain this. I also believe zoos are integral in conservation of species with reintroduction programmes involving wild-caught animals in the correct social situation as well as ones bred in captivity are vital and the correct measures are being taken to do this.
References
Blackshaw, J.K. (1986) Notes on some topics in Applied Animal Behaviour 3rd Edition. Chapter 10: Wild Animals In Captivity.
Clubb, R. & Mason, G. (2003) Captivity effects on wide-ranging carnivores. Nature 425:473.
Clubb, R. & Mason, G. (2007) Natural behavioural biology as a risk factor in carnivore welfare: How analysing species differences could keep zoos improve enclosures. Applied Animal Behaviour
Gilbert-Norton, L.B., Leaver, L.A. & Shivik, J.A. (2009) The effect of randomly altering the time and location of feeding on the behaviour of captive coyotes (Canis latrans). Applied Animal Behaviour Science 120(3-4):179-185.
Hayward, M.W. & Somers, M.J. (2009) Re-introduction of Top-Order Predators. Chapter 12 – The role of social behaviour in carnivore re-introductions. Blackwell Publishing.
Hosey, G., Melfi, V. & Pankhurst, S (2009) Zoo Animals: Behaviour, Management and Welfare. Oxford University Press.
Jule, K.R., Leaver, L.A. & Lea, S.E.G. (2008) The effects of captive experience on reintroduction survival in carnivores: A review and analysis. Biological Conservation 141:355-363.
Kistler, C., Hegglin, D., Würbel, H. & König, B. (2009) Feeding enrichment in an opportunistic carnivore: The red fox. Applied Animal Behaviour Science 116(2-4):260-265.
Kleiman, D.G., Thompson, K.V. & Baer, C.K. (2010) Wild Mammals in Captivity: Principles and Techniques for Zoo Management, 2nd Edition, Pg. 14. University of Chicago Press.
Mason, G., Clubb, R., Latha,, N. & Vickery, S. (2007) Why and how should we use environmental enrichment to tackle stereotypic behaviour? Applied Animal Behaviour Science 102(3-4):163-188.
Mellen, J.D. & Wildt, D.E. (1998) Husbandry Manual for Small Felids. American Zoo and Aquarium Association.
Quirke, T. & O’Riordan, R.M. (2011) The effect of different types on enrichment on the behaviour of cheetahs (Acinonys julbatus) in captivity. Applied Animal Behaviour Science 133(1-2):87-94.
Tilson, R., Brady, G., Traylor-Holzer, K. & Armstrong, D. (1994) Management and Conservation of Captive Tigers, 2nd Edition. Chapter 4: Nutrition, Food Preparation and Feeding.
University of Exeter (2008) Captive Carnivores Not up To Wild Living. Science Daily (online) 21st January. Source: www.sciencedaily.com/releases/2008/01/080121080406.htm. Last accessed: 20/Dec/11.
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