Ideal Free Habitat Selection and Consumer-Resource Dynamics

In landscapes in which habitat patches are larger than the home ranges of consumers, ideal free habitat selection is incompatible with pseudointerference. Source-sink dynamics and spillover consumption can be generated only by nonequilibrium situations. At equilibrium, patterns in consumer and resource standing crops and resource mortality are identical to those generated by local dynamics. Predictions of laissez-faire models are relatively robust to feeding interference. Habitat selection of armored catfishes and their interactions with attached algae in a Neotropical stream are consistent with predictions derived by assuming laissez-faire consumer-resource dynamics and ideal free habitat selection, in spite of the limited mobility of consumers and the occurrence of substantial feeding interference. We propose that the simple null model of ideal free habitat selection plus laissez-faire consumption applies to the majority of herbivore-plant systems, because of the even distribution of resources and the lack of efficient weapons in consumers.