Consumer demand under commercial husbandry conditions: practical advice on measuring behavioural priorities in captive animals

Abstract

AbstractIn recent years, consumer demand studies have been used to objectively quantify the value that captive animals place on environmental resources. Considerable progress has been made in the development of effective methodologies to assess what resources are valued under controlled experimental conditions, but few of the findings from these studies have been implemented in commercial husbandry systems. A major obstacle has been the need to maintain internal validity in experimental studies at the possible expense of external validity. Experimental subjects may be poor representatives of commercially kept animals, especially where there is no replication of the animal's experience of commercial physical and social environments. This paper will discuss means of increasing the external validity of consumer demand studies. Firstly, experimental animals should be of representative genotypes, reared under commercial conditions and housed in test apparatus with free access to all of the resources that are normally available under commercial husbandry conditions. As well as providing a long-term closed economy, this allows manipulation of potentially important environmental factors such as prior experience. Secondly, naturalistic tasks should, where possible, be used in preference to abstract operant tasks since they appear to be easier to train animals to associate with rewarding resources, therefore many individuals can be investigated efficiently. Furthermore, naturalistic tasks appear to be less prone to operant bias than artificial tasks and can provide robust measures of value in terms of the maximum price paid for access to resources. Finally, for group-housed species, social costs such as enduring higher stocking densities and/or competition for resources may be an effective means of investigating cost-benefit trade-offs under commercial conditions. For example, if animals work to evenly distribute themselves over available space, this social spacing priority can be used to investigate whether they will endure higher stocking densities in order to exploit particular resources.