Extension of ideal free resource use to breeding populations and metapopulations

The concept of an ideal and free use of limiting resources is commonly invo ked in behavioural ecology as a null model for predicting the distribution of foraging consumers across heterogeneous habitat. In its original concept ion, however, its predictions were applied to the longer timescales of habi tat selection by breeding birds. Here I present a general model of ideal fr ee resource use, which encompasses classical deterministic models for the d ynamics in continuous time of feeding aggregations, breeding populations an d metapopulations. I illustrate its key predictions using the consumer func tional response given by Holling's disc equation. The predictions are all c onsistent with classical population dynamics, but at least two of them are not usually recognised as pertaining across all scales. At the fine scale o f feeding aggregations, the steady state of an equal intake for all ideal f ree consumers may be intrinsically unstable, if patches are efficiently exp loited by individuals with a non-negligible handling time of resources. At coarser scales, classical models of population and metapopulation dynamics assume exploitation of a homogeneous environment, yet they can yield testab le predictions for heterogeneous environments too under the assumption of i deal free resource use.