Man's first efforts to keep wild
animals in captivity date back to prehistoric times, and for many
reasons humans are attracted to non-human animals.
The animals people expect to see in
zoos are those they have learned about in books as children, and
those seen in television specials. People will usually stop, at
least momentarily, for
1. animals that beg
2. animals that are feeding
3. baby animals
4. animals that make sounds
5. animals that are mimicking
human behaviour, or playing
They pay little or no attention to
nesting, sleeping or hiding animals (Ludwig, 1981). Many people
dislike zoos and many people enjoy them. Yearly, more than 100
million Americans visit zoos and people are fascinated by wildlife
in captivity (Eaton, 1981).
In the past, some zoos paid little
attention to the welfare of the animals, and some zoos today have
poor environments for the animals. But zoos are undergoing a
revolution that is providing better physical and social environments
for animals. Progressive zoos are engaged in education, research and
conservation, with the aim of maintaining healthy animals that
behave in a natural way.
Hediger (1964) was the first person
to document biological and ethological principles important for the
welfare of captive animals in zoos. By understanding an animal’s
behaviour, facilities that cater for the animal’s needs can be
designed.
CATCHING AND MOVING ANIMALS
In Africa, the catching of large
wild animals in sufficient numbers for stocking or restocking game
farms, reserves and parks is a frequent occurrence. Many zoos today
obtain stocks of animals bred in captivity, so the trauma of capture
is no longer necessary, although the transport of animals will cause
some stress.
Wherever possible, animals that need
catching for movement or treatment in Safari Park-type animal
reserves should be fed or driven into transporting crates. These
methods can be used successfully, particularly for giraffes,
elephants, and some of the antelope, as well as for cheetahs and
young lions (Tennant and Chipperfield, 1972). The design of the
buildings and enclosures in which the animals are kept contributes
to the success of these methods. Funnel-shaped rails leading into a
crush that the animals are used to are invaluable for loading
animals like giraffes and antelope. Doors to houses for big cats
should be of the sliding or trap kind to facilitate loading and
unloading travelling crates.
Giraffes are usually moved in groups
of two to seven in very large crates, and antelopes are usually
crated individually. Male animals are never mixed because of the
risk of fighting. Zebra should be crated individually. Many animals
(elephants, rhinoceroses, hippopotamuses, lions, etc.) are more
easily moved if they are immobilised or tranquillized and a dart gun
may be necessary (Tennant and Chipperfield, 1972).
1.
Space and environment
2.
Food
3.
Social structure and breeding
requirements
4.
Man-animal relationship
5.
The effect of caging on
behaviour
Space and environment
Good management should provide
conditions that substitute beneficial factors which influence the
species in the wild, and remove factors that have an adverse effect.
It is not possible to give an animal an exact replica of its
environment but animals have the ability to adapt to a wide range of
conditions. For each particular stress factor each animal has a
range – the Normal Adaptive Range – which it can
tolerate and react to normally. The limits of this range vary for
each animal, its age and sex, and are never precise. Outside these
limits the animal becomes uncomfortable and at greater extremes it
may become so stressed that it is susceptible to disease and injury
and is unable to adapt. Death may eventually result.
The goal of a zookeeper is to
provide an animal with an environment similar to its natural
environment in which it can survive and reproduce. To do this, it is
necessary to understand how a species occupies space in a natural
state. There are some important questions to answer:
1. What is the geographical range
of the species? There are definite limits to this range which may
be physical (mountains, rivers, seas), or environmental
(temperature, humidity, rainfall). These limits, in turn,
determine the type of vegetation the animal inhabits and the food
it eats.
2. In what local habitat does the
animal live and how does it use its limbs to move about in this
habitat?
3. Each species has its own
territory or habitat, which supplies particular needs. This
habitat may be occupied by more than one species using different
parts of the habitat. Sometimes the same part is used by another
species but at a different time. Leopards are cats that habitually
lie up in trees, while many other carnivores and most ungulates
live on the ground. Within the habitat is the living area for a
family – and this contains the personal space of each individual.
However, the animal is not free but is spatially bound to its
territory, which it marks and defends. If a space falls vacant, it
is at once seized by a member of the same species.
The normal sleeping pattern and
sleeping place of the species should be known. Some animals sleep
in protected places, others sleep in the open. The place of refuge
from danger is also important. Some animals flee in danger, others
become immobile, some run up a tree, others run underground.
The concept of habitat or territory
has important consequences for the correct handling and design of
environments for animals in captivity. Their cage or enclosure must
be arranged so that the animal accepts it as its personal property
and consequently marks it and defends it. Different sized animals
have different sized territories and many predatory carnivores have
far bigger territories than their prey, often herbivores.
Food
On what does the animal feed and how
much of its time is spent searching for food? This is an important
question. There are three aspects to consider:
1. The animal must have an
adequate diet nutritionally to maintain a healthy and thriving
condition.
2. The food must be of the correct
bulkiness for the digestive system.
3. Food should be presented in
such a way that the animal spends as much time eating as it would
in the wild.
This question of feeding behaviour
presents difficulties. Carnivores normally hunt and kill their prey,
but this cannot happen in a zoo as the welfare of the prey is as
important as that of the carnivore and also most of the public would
find it unacceptable. However, the carnivores, after eating, spend
most of their time sleeping, so do not have a problem of filling in
time.
On the other hand, plant-eaters
present more of a problem as they normally spend much of their day
feeding (cows spend about eight hours/day grazing, sheep about 10
hours/day). It is very difficult to provide these animals with a
substitute diet that would take them most of their waking hours to
consume.
Social Structure and Breeding Requirements
Some animals are solitary, except
when the female comes into season. Polar bears and giant pandas are
in this group. Some animals form single male bachelor groups, except
during the breeding season, and many matriarchal groups consist of
the older females and their offspring. In any group of animals a
social organisation evolves, often an elaborate hierarchical
structure, especially in male groups, involving ritual behavioural
displays. It is important to understand the social structure and
breeding requirements if the animal is to reproduce in captivity.
Many species do not come into breeding condition without the
stimulus of introduction to the opposite sex. Cheetahs kept together
in pairs do not breed, but when reunited after separation they may
do so. Some species rely on the stimulus of daylength to come into
season or rut. Others do not need this stimulus and are able to
breed throughout the year.
An example of a problem of breeding
that was solved by studying the animal’s social structure and
behaviour, was seen in a small herd of Father David's deer (Crowcroft,
1978). Two males and three females were in the group, in good
health, but not producing young. One summer a group of students
studied the social behaviour within the herd. It was eventually
concluded that the behaviour of the dominant stag was a major
obstacle to breeding. He covered only one female, an elderly hind
beyond breeding age. He did not show any interest in the other
females, but he would not allow the younger stag to mount any of the
females. The following season, by locking up the old stag and
letting the younger one remain with the females, a birth was
achieved.
Man–Animal Relationship
When an animal is moved from its own
environment into captivity, it must reconstruct a whole new world
and this is an enormous task. Two types of behaviours emerge:
1. The animal may settle down in
its new environment. This is often seen in the undeveloped, still
adaptable young wild animal.
2. The animal may never settle
down, even if kept in captivity for a long time.
In man's mind, the amount of space
at an animal’s disposal is often regarded as the most important
consideration. It has been mentioned already that a free animal
has a specialised and limited territory, so the quality of the
space for the animal is more important than the quantity.
When an animal is in captivity there
are both primary effects and secondary effects of space restriction.
The primary effect is the restriction of movement and the secondary
effects include lack of diversion and occupation, no food choice,
impossibility of avoiding its own species at will, possible
unsuitable differentiation of space, anti-social behaviour.
Then there is the problem of
deciding what amount and design of space is necessary for an animal.
The flight reaction is the most significant behaviour pattern of the
wild animal’s life in freedom so it should be of prime concern in
captivity. In theory, the smallest cage should have a diameter twice
the flight distance (F.D.), e.g.
In this way, an animal could retreat
to the centre of the cage away from man, who appears as an enemy.
This is often impossible to accommodate so the solution is to reduce
the flight distance and so neutralise the animal’s desire to escape.
This is possible by taming. Zoos now often receive animals bred in
captivity, whose flight distances are greatly reduced from their
wild ancestors.
Effect of Enclosures on Behaviour
It is important to ask the question:
Is the behavioural limitation that caging imposes necessarily
harmful?
1. One effect of moving an animal
from the wild to a cage is to remove it from a rich and varied
environment, this may cause it to indulge in one activity to an
abnormal degree to compensate for other activities that are no
longer possible.
2. Another effect may be
over-grooming behaviour of a mother towards a new-born. She may
continue to lick after the afterbirth has been removed and the
young is clean, so damaging the skin. This may eventually lead to
wounding and biting young to death.
3. Caging removes the necessity to
hunt for food, but elaborate hunting sequences may still be
carried out which are now inappropriate, e.g. wild racoons kill
their prey from the river by shaking it. Captive racoons may carry
bread to the water bowl and re-enact the killing of the prey.
4. When natural behaviours are
frustrated, increased aggression to cage-mates, and sometimes
self-directed harm, may result.
These are all important factors when
considering the welfare of captive animals.
How can conditions be improved in zoos?
The layout of many zoos is
dramatically changing – gone, or at least going, are the inner-city
animal slums, and new zoos are trying to approximate the open
condition of the wilds. England's Whipsnade
Park became the prototype for
open-range exhibits in 1932 and many zoos now house animals in
similar conditions to their wild state.
Other suggestions include teaching
animals tricks so they can perform, training them to work for food
and environmental comforts; all this helps fill in time and provides
activity.
More common now is the philosophy
that different zoos should become specialist centres for certain
groups of animals, rather than every zoo keeping just one example of
a species. In this way certain zoos could specialise in rare species
both for replenishing their own exhibits and for replenishing wild
stocks. These centres could be financed by zoos, conservation
societies, and the general public.
There is the question of zoo animals
living to old age and suffering various complaints. This is actually
unnatural in the wild where survival of the fittest is the rule. The
ethical question arising is – should man, who is responsible for
lengthening the life of the animal, put the animal painlessly to
death in old age or because of disease? Also, what happens to
animals that are reproducing at too great a rate? Over-production
may occur in lions, brown bears, the males of some species of
antelope, deer and cattle. It is difficult to release them to the
wild after they have been bred in captivity; they would be harassed
by their own species, lack the skills to hunt and may die of
starvation. The ethics of killing these animals due to lack of space
should only be a last resort.
The final question asked by many
people is: Is it really necessary to keep animals in captivity?
Certainly it is necessary in some cases to carry out experiments
under laboratory conditions on pest species so it can be determined
the most effective and humane means of controlling excess
populations of these animals in the wild. But what about zoo
animals? Many believe that television provides us with a close-up
account of these animals but does it take the place of studying the
animal at close quarters?
Progressive zoo management should
promote animal behaviour as a scientific field with the study of
wild animal medicine and management and perhaps the study of
environmental design.
People will probably always go to
zoos for recreation to see the animals, so in the process they
should be educated also, and it is the behaviour of the animals that
provides the education.
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