ELEMENTS OF A SYSTEMATIC SEARCH IN ANIMAL BEHAVIOR AND MODEL SIMULATIONS

Starting from a position paper by Hans Bremermann, general aspects of search behavior are envisaged: locomotion itself, the capability of or ientation and possible storage of information about the 'goals' of a s earch. The importance of stochasticity in these processes is briefly d iscussed. In particular, experimental findings and theoretical concept s on the homing search of desert isopods (Hemilepistus reaumuri) are p resented. Using the general framework of stochastic differential equat ions for the angular turning rate of a migrating individual, search pa ths with characteristic loops and meanders can be modelled and simulat ed. Search success is quantified by measuring the degree of path overl ap and by computing an index of area search intensity. Quantities are plotted versus path length, both for observed isopod data and for typi cal simulated search paths. Certain elements of a systematic search ar e described and explained by a hypothesis about temporal locomotion co ntrol, based on the isopod's ability for path integration and directio nal compensation. Finally, possible effects of orientational cues are mentioned.