When both types of behaviour are equally weighted, the pattern of investment depends on competitive asymmetry. For low asymmetry levels, both chicks invest in signalling. For large asymmetries, the less competitive chick invests in signalling and the more competitive chick invests in non-signalling behaviours. In Model 2, food allocation is determined by the product of the signalling and non-signalling intensities. Larger chicks invest more in signalling and less in non-signalling behaviours.
Larger chicks get more food than their siblings.
A comparison of the different models shows that the chicks waste more resources when signalling evolves. Hence, if natural selection could act on the mechanism of food distribution, we would expect signalling to play a minor role in the actual pattern of allocation of resources.