Diagnosing Abnormal Behaviour

Before instituting any form of treatment or attempting to correct abnormal behaviour it is important to develop an understanding of the animal’s behavioural history. Any animal with a behavioural problem should be examined and treated for concurrent medical problems. The Ethogram can also be used to provide background information on the animal’s natural behaviour. Understanding the natural behaviour patterns of different species and individuals can help with diagnosing abnormal behaviour. Aspects to consider when establishing the history of an individual animal should include the following:
  • Environment: Consider the animals’ entire environment, for example, the schedule of keepers who are in contact with the animal, the amount of exercise the animal has, the reaction and behaviour of keepers and visitors when they encounter the animals’ abnormal behaviour etc. Does the behaviour only occur at a certain time or in a certain place?
  • Early history: The early history of an animal may give clues to exhibited behaviour. What was the background of an animal before it came into the enclosure? How has the animal been handled since coming in to its new environment?
  • Training: Any training an animal has received that may be relevant.
  • Other behavioural problems: Does the animal exhibit any other behavioural problems?

Below are some examples of abnormal behaviours that can be observed in zoo animals:
  • Abnormal aggressiveness – sudden bouts of aggressive behaviour can be due to the restrained life of some larger carnivorous animals. Abnormal aggressive behaviour can also be targeted at social partners, other animals or a particular person.
  • Altered time budgets – the allocation of time for particular behaviours is very different from in the world.
  • Bar biting – can be displayed by various species including bears and captive pigs.
  • Abnormal mother-offspring relations
  • Abnormal escape reactions – violent escape reactions (throwing themselves against the walls of enclosures.
  • Fearful behaviour – avoidance, shivering, sweating or over-reaction to minor environmental changes
  • Food refusal – in large cats, refusal of food can often occur after capture or a change of housing.
  • Increased frustration and conflict behaviour – such as displacement behaviours or behaviours that are out of the normal range for the animal such as head-shaking, scratching, chewing or licking.
  • Motor inhibition – common in newly relocated animals, the animal is so frightened in the presence of keepers that it will stand in one place without moving.
  • Repetitive movement with no obvious function (stereotyped behaviour) – eg. pacing, weaving, swaying, circling and head nodding.
  • Ontogenic behavioural changes – the animal does not display normal behaviours for its species at their particular age or stage of development.
  • Self-mutilation – such as feather-pulling in some parrot species.

Interestingly, some animal behaviour experts believe that some abnormal behaviour such as pacing can actually help animals to cope with the adverse conditions they live in. These researchers believe that halting these behaviours can be damaging to the welfare of the animal. It is important to address why these behaviours are occurring and then make changes to improve the welfare of the animal rather than masking the problem.