Practical Issues > Animals Used for Entertainment > Zoos - Index


    Throughout the world including the UK, thousands of zoo animals held in artificial environments with little stimulation, enrichment or opportunity to hide from the public gaze, display unnatural behaviour patterns. Even in the 'better' zoos, abnormal behaviour can be widespread, and include repeated pacing, rocking, vomiting and even self mutilation.

    Some of these 'stereotyped' behaviours displayed by bored and frustrated animals have their basis in activities that occur naturally the wild. But in the impoverished confines of captivity, these behaviours can become compulsive and unnatural.

    In 1992, Bill Travers first coined the term 'zoochosis' to describe this obsessive, repetitive behaviour, and described zoo animals behaving abnormally as 'zoochotic'. The terms are now widely recognised and in the public domain, being used in a wide range of journals and publications.

    Abnormal behaviours

Bar biting

The repeated biting, rubbing the mouth along, or even sucking on the bars of an enclosure, which can result in damage to teeth and the mouth area particularly if the bars are rusty.
Can be displayed by captive bears

Tongue playing
The continual licking on walls, bars or gates in an enclosure.
Can be displayed by giraffes and camels 

Continuous walking back and forth, following the same path. Signs of regular pacing include definite paths worn in the ground.
Can be displayed by big cats 


An acute form of pacing, the following of a defined route placing feet in exactly the same position each time.
Can be displayed by elephants & bears

Neck twisting

Unnatural twisting and rolling of the neck, often flicking the head around or bending the neck back. It can be combined with a pacing behaviour.
Can be displayed by giraffe, llama & monkey species


A form of 'bulimia', the repeated vomiting, eating of vomit and regurgitation.
Can be displayed by gorillas & chimpanzees


Playing with and eating excrement, smearing it on wall and glass.
Can be displayed by gorillas & chimpanzees

Sitting, sometimes hugging the legs, rocking forwards and back. A recognised symptom of mental illness in humans.
Can be displayed by chimpanzees


Standing in one place and swaying the head and shoulders, even the whole body, from side to side. A behaviour exhibited by mentally ill humans.
Can be displayed by elephants & bears

Head bobbing & weaving
Standing in one place and continuously moving the head up and down, or weaving to and fro.
Can be displayed by bears and elephants


Grooming to an excessive extent, pulling out hair or feathers, often leaving bald patches, irritated and broken skin.
Can be displayed bears & parrots

Self mutilation
Self-inflicted physical harm, such as biting or chewing tail or leg, or hitting a head against a wall.
Can be displayed by big cats, bears & primates

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