Born Free Foundation - Keep Wildlife in the Wild

Zoochosis: Abnormal and Stereotypic behaviour in Captive Animals

Ensuring reasonable animal welfare in captivity is extremely challenging. Animal species have evolved over millennia and their physical, physiological and behavioural traits have developed in order to optimise their chances of survival in their natural environment.

In captivity, animals may face a number of challenges for which evolution has not prepared them. The climate, diet and the size and characteristics of the enclosure may be completely alien to the species as it exists in the wild.

Captive animals may no longer be able to have control over their environment, nor carry out evolved behaviours aimed at enhancing their welfare or survival prospects. Instead they must rely on humans to provide for many of their physical, social, biological and other needs.

If the captive environment does not cater for the species-specific needs of the animal, there can be a deterioration in both physical and mental health such as the development of abnormal behaviour, disease and even early mortality.

Similarly, invasive interventions such as the restriction of movement, training using negative reinforcement techniques, being trained to preform unnatural behaviours or making modifications to the normal physiology of animals to reduce risks when handling, can cause severe and lasting distress.

Abnormal behaviour can include stereotypic behaviours - repetitive behaviours which appear to have no obvious goal or function - such as repetitive pacing, swaying, head-bobbing or circling and bar-biting ‘demonstrably caused by the frustration of natural behaviour patterns, impaired brain function, or repeated attempts to deal with some problem’ (Mason, 2005); over-grooming, excessive licking and vocalisation are recognised as displacement behaviours, ‘arising out of conflict when an animal is driven to perform two behaviours at the same time’ e.g. conflict between the fear of the keeper and the desire to get food (Bacon 2011); apathy and redirected aggression.

Further explanation on abnormal behaviour and examples:

Pacing and circling

Continuous walking back and forth or in a circle, following the same path. Signs of regular pacing include definite paths worn in the ground. Seen in many captive animals, especially big cats and canids (eg wolves).

See video example

Bar biting and tongue playing

Tongue-playing and Bar-biting

The continual licking, sucking or biting of walls, bars or gates in an enclosure. Often seen in giraffe and primates.

See video example

neck twisting

Neck twisting

Unnatural twisting and rolling of the neck, often flicking the head around or bending the neck back. It is often combined with pacing behaviour. Seen in e.g. giraffe, llama, bears & primates.

See video example

swaying weaving head bobbing

Head bobbing, Weaving and Swaying

Standing in one place swaying the head and shoulders, even the whole body, from side to side, moving the head up and down, or weaving to and fro continuously. Seen in e.g. bears and elephants.

See video example



Sitting, sometimes hugging the legs, rocking forwards and backwards. Seen in e.g. captive ape species. 

See video example

Overgrooming and Self Mutilation

Self-inflicted physical harm, such as biting or chewing tail or leg, or hitting a head against a wall, grooming to an excessive extent, pulling out hair or feathers, often leaving bald patches, irritated and broken skin. Seen in e.g. apes, bears, parrots and big cats

See video example

vomiting and regurgitation

Vomiting and Regurgitating

A form of 'bulimia', the repeated vomiting, eating of vomit and regurgitation. May be linked to the captive diet. Seen in e.g. captive ape species.

See video example


Coprophilia and Coprophagia

Playing with and eating of excrement (in species that do not naturally do this) or smearing faeces on enclosure walls and glass. Seen in e.g. captive primate species.

See video example

Other forms of stereotypic behaviour seen in captive wild animals includes: Apathy, where an animal is abnormally passive and does not react to stimuli. Occurs particularly when social animals are separated from companions; Abnormal mother-infant relationship, where mothers attack, abandon or kill their offspring, or where mothers wean offspring too soon or too late; Prolonged infantile behaviour, where animals do not mature properly or acquire aberrant social behaviours e.g. excessive crying or vocalisation, lack of social confidence, lack of secondary sexual characteristics; Abnormal aggressive behaviour, where aggression is uncontrolled, in terms of intensity and frequency, or directed to the wrong individuals or objects. This can be the result of overcrowding, threats by social dominants, isolation from companions or pressure from zoo visitors.


In 1992, Bill Travers, co-founder of the Born Free Foundation, first coined the term ‘zoochosis’ to describe this obsessive, repetitive behaviour, and described zoo animals behaving abnormally as ‘zoochotic’.

In 1993, the Zoo Check Charitable Trust (now the Born Free Foundation), produced The Zoochotic Report,  video observations by the late Bill Travers, taken over 3 years in over 100 zoos in Europe, North America and the Far East. The Zoochotic Report raised serious concern about the effects of captivity on wild animals. The Report helped form the philosophies for our organisation and its animal welfare objectives.

“In every zoo I visited when compiling the Zoochotic Report, I witnessed some sort of abnormal behaviour” Bill Travers, Co-Founder of the Born Free Foundation.

Born Free Foundation
Broadlands Business Campus, Langhurstwood Road
, Horsham, RH12 4QP, UK - Charity Reg. No. 1070906

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