Working for a dustbath: are hens increasing pleasure rather than reducing suffering? Applied Animal Behaviour Science 68, 39-53 (2000)

Widowski, T. M., Duncan, I. J. H.

Abstract

Dustbathing is one of the major behavioural systems of domestic fowl that is constrained by commercial caging systems. ... In this study, we measured hens' willingness to work to obtain substrate for dustbathing using a vertically swinging door to which weights could be added. Hens were trained to pushthrough the door to enter a goal box containing peat moss. ... The results of these trials indicate that although deprived hens may be more motivated to dustbathe, and that most hens may be willing to work to obtain a dusty substrate when they can see it, they are not necessarily willing to work harder when they are in a state of deprivation than when they have recently dustbathed. These results are very difficult to explain using a `needs' model of motivation in which deprivation leads to a state of suffering. They are much more consistent with an `opportunity' model of motivation in which performance of the behaviour, when the opportunity presents itself, leads to a state of pleasure.