The value of information in central-place foraging


E. J. Collins, A. I. Houston and J. M. McNamara
We consider a central place forager with two qualitatively different types of food sources; type 1 sources are always available whereas type 2 sources become available intermittently and this availability is signalled by information present at the central place. Source 1 is modelled using a standard patch foraging model whereas source 2 is modelled somewhat schematically in terms of the presence of information, the time spent at the source and the average reward received. The only decision in the model is the time spent by the forager at source 1 on each trip. We characterise the optimal foraging time and the optimal overall reward rate under the two source model and compare it with the corresponding quantities for a single source model. We show that, in general, the potential for information transfer has a marked effect on the foragerís behaviour, and that a forager behaving optimally should return to check for new information with what might, under a single source model, seem to be a strictly submaximal load. We consider the dependence of the optimal foraging time and the optimal overall reward rate on the source 2 model parameters, and also show that our qualitative results hold for a variety of models for the time spent on source 2.

Some key words:
central place foraging, optimal foraging time, two source model, partial loads.