OPTIMAL SINUOSITY IN CENTRAL PLACE FORAGING MOVEMENTS

The case of a forager searching for immobile, randomly distributed prey items from a central place and homing straight back was examined to determine the optimal sinuosity of the search path. The optimal policy that was considered consists of minimizing the expected total (searching plus homeward) path length required to survey a given area, depending on the number of prey items the animal is able to load, its search path width and the prey density. The sinuosity of the search path must be low enough to minimize any overlapping between search path loops but high enough to minimize the homeward journey. Because of the complexity of the mathematical approach, the optimal sinuosity formula was derived using computer simulations. For a given prey density, the optimal sinuosity decreased logarithmically with the number of prey items the central place forager was searching for. The optimal sinuosity formula was also extended to deal with patchy environments. The applicability of this formula and its robustness to errors in the animal's estimate of the prey density are discussed. © 1991 The Association for the Study of Animal Behaviour.