Signalling need: costly signals and animal welfare assessment
Publication Type: |
Journal Article |
Year of Publication: |
1995 |
Authors: |
D.M. Weary, D. Fraser |
Publication/Journal: |
Applied Animal Behaviour Science |
Keywords: |
animal well-being, honest signalling, pigs, stress, vocalization |
ISBN: |
0168-1591 |
Abstract:
If animals signal their level of need for certain resources, scientists should be able to use these signals in assessing animal well-being. Theoretical models show that, under certain conditions, natural selection can favour the evolution of “honest” signalling systems, where vocal and other natural signals provide reliable indicators of the signaller’s needs. These conditions include that signaller and receiver are related, that signallers vary in their degree of need for a response, and that producing the signal entails some “cost” in terms of individual fitness. Arguably, these conditions are met by vocal signals given by piglets when separated from the sow (as in weaning) or when injured (as in castration), and initial experimental results suggest that variation in these signals provides information on the animals’ welfare. However, as not all signals relate to need, researchers should attempt to understand the natural function of a signal before invoking it as a measure of well-being.