Aquatic Zoos - Captive Animals Protection Society

The only common quantifiable behavioural aspect for all stereotypes using Odberg’s definition is the
concept of repetition. Authors differ as to just how rigid or repetitive a behaviour pattern has to be
before they will call it a stereotypy (Forrester, 1980; Broom, 1983; Fraser and Broom, 1990), but some
studies using informational redundancy to quantify the repetition within behavioural sequences (Stolba et
al. 1983) concluded that repetitions of three or more times in a 30 seconds assessment period agreed
with the results of information-redundancy analysis. Other work in stereotypy in mink also uses three
successive repetitions of a movement or sequence of movements as a criteria to identity stereotypies
(Mason, 1994).
In this investigation the criteria of ‘at least three repetitions in half a minute’ to categorise a behaviour as
possibly stereotypic was also used. However, that was only the criteria used to identify a ‘possible’ case
of stereotypy that would require further observation before confirmation. Therefore, if during the
aquarium visit an animal was seen performing any sort of repetitive behaviour with no apparent function
at least three times in a row, the animal was identified as ‘possible stereotypic animal’, and its behaviour
was then video recorded for a sufficient period of time to allow confirmation of stereotypy –which often
implied returning to the exhibit several times during the visit.
Once all possible cases of stereotypic behaviour were recorded, they were classified in the following
categories:
Pacing: Continuous walking/swimming to and fro, following the same path (or several similar
paths), from one point of the exhibit to another, when performed with no apparent special response
to a transparent boundary (i.e. glass). See figure 6.
Figure 6. Butterflyfish pacing in a UK public aquarium
Circling: A form of pacing where the animal continues around a circular path with no points easily
singled out of where it ends or begins. See figure 7.
Head bobbing & swinging: Staying stationary in one place and continuously moving the head up
and down, or swinging it left and right, when performed with no apparent special response to a
transparent boundary (i.e. glass).
26