Thwarting of behaviour in different contexts and the gakel-call in the laying hen

Earlier studies have shown that thwarting of feeding behaviour in the layin g hen is expressed through a specific vocalisation, the gakel-call. The fir st aim of this study was to investigate whether the effect of deprivation p er se on the occurrence of gakel-calls can be distinguished from the effect of the additional frustration. Frustration is defined as the state of an a nimal that results from nonreward in the expectancy of reward. The second a im was to investigate whether the occurrence of gakel-calls is restricted t o a food context or whether it can be regarded as an expression of frustrat ion in general. For this purpose, 20 hens were deprived of food, water and dustbath. After deprivation at a fixed time, a cue was given and the hens w ere rewarded with access to food, water or dust during a 15-min session on 4 consecutive days. On the fifth day, they were thwarted in the associated behaviours by blocking the access to these commodities, after the hens had been presented the signal that previously preceded the reward. We then reco rded behaviours that might reflect: the state of frustration in three 15-mi n periods. The period "Pre-Frustration'' started 15 min before "Frustration ''. This, in turn, was followed by the period "Post-frustration" in which t he hens were rewarded again. Nesting behaviour was thwarted by blocking the access to the nest (Frustration) after a hen had reached the last stage of its prelaying behaviour. In the food, water and dustbath context, deprivation elicited gakel-calls. The additional frustration resulted in a higher number of gakel-calls in al l contexts except the food context. However, together with the findings of previous experiments, the results of this study suggest that frustration, i n general, is expressed through the gakel-call. Frustration in the nest con text elicited more gakel-calls than the other contexts. This latter finding is discussed in the light of the occurrence of the gakel-call under natura l circumstances. (C) 2000 Elsevier Science B.V. All rights reserved.