ABSTRACT
The basic formulation of many foraging models has been adapted directly from the fields of economics and operations research for which state spaces and constraint sets may be well bounded. The foraging herbivore either makes or has imposed upon it decisions that determine: how much time to spend foraging, how to partition that time and how intensively to utilize the time spent foraging. Young animals that are still suckling have less need to allocate time to foraging and may be constrained by greater requirements for rest and play. Treatment of potential environmental constraints on the time allocated to foraging is often ambiguous. However, when daylight foraging is decreased, nocturnal foraging may increase so that the total time foraging remains unchanged. Total time spent foraging should decline as it becomes more profitable to forage. Profitability of foraging can be influenced by forage biomass density, tiller length, or digestibility.
