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Considerations for Devising New Techniques

By Dr Rob Young
Research -Co-ordinator

1. The device must not pose any threats to the animal’s safety (Bloomsmith et al 1991). Therefore;

• It should not contain holes that digits or other bodily appendages can get stuck into.
• It should be able to withstand severe physical abuse by the animal species without breaking.
• It should not be made of a material that would be toxic if the animal managed to chew or gnaw pieces of the device.
• It should not be of a size that could be swallowed by the animal.
• The device should not contain any parts in which the animal could either become entangled or strangulated.

Thus, all devices should be assessed for safety and where appropriate undergo ‘abuse tests’ (simulations of destructive children getting their hands on the device). Free hanging ropes are potentially dangerous in the enclosure of any species, since animals may become entangled and strangled; thus both ends of a rope should be attached to a solid structure.

2. The device must not be able to be used as a weapon by a particular species on other occupants of its enclosure, against keepers, or the visiting public (Bloomsmith et al 1991). For example, certain chimpanzees are notorious throwers of objects (Goodall 1986) as are some elephants (Dittrich 1984); this is especially important if the object is large and heavy. It is important to remember that food can also be used as a weapon; for example, imagine being hit by a whole turnip thrown by a chimpanzee!

3. The device must not have any potential to be used by the animal to escape its enclosure. For example, devices that have long sections must be installed in such a way that they could never be used for escape. In a number of cases chimpanzees have used enrichment objects in their enclosures to scale the perimeter fence of their enclosure (Dittrich 1984).

4. It is important to remember that with certain species; keepers have little control over them; for example, polar bears. Therefore, devices that must be retrieved from the enclosure for refilling are of little use. In the middle of the Chimpanzee enclosure at Edinburgh Zoo there is an excellent artificial termite mound (1982), which many of the chimpanzees like to fish from. However, to refill the termite mound keepers must enter the outdoor enclosure, but the chimpanzees rarely co-operate by going inside.

5. Certain species have great dexterity and patience for solving problems, which may be used to dismantle enrichment devices making them of little value (e.g., all of the great apes, especially the orang-utans). Furthermore, a fully assembled enrichment device may pose no threat to the animal, whereas a dismantled one may be dangerous or used as a weapon or to escape the enclosure. Thus, where appropriate very strong locks should be fitted on enrichment devices.

6. Devices should be cheap to construct and of the simplest design possible, so that they are as widely available as possible. Spending much money on one enrichment device is not cost effective.

7. In countless zoos throughout the world enrichment devices are sitting unused, because they are not very practical. Thus, all enrichment devices should be cleaned, maintained and easily filled, as keeper time is often limited (Hayes 1990).

8. It is important that enrichment devices installed in animal enclosures, do not block or obstruct keeper access to the enclosure (Markowitz 1982).