On the Foraging Activity of the Wood Ant

Abstract

The movement of animals in search of food is one of the primary causes of their dispersion over the area which a population comes to occupy. As such its study, as well as being of considerable theoretical interest, has potentially some practical importance. For example, these movements probably determine the average age at which young plaice (Pleuronectes platessa) appear on the main fishing grounds for that species in the southern bight of the North Sea. It seems that their general offshore displacement from the so-called 'nursery grounds' off the Dutch coast can be regarded as analogous to random diffusion in physical systems, at least until the basic pattern is modified by the onset of sexual maturity and the consequent highly oriented spawning migration during successive winters. Some of the problems arising from local movements in fish populations have been discussed elsewhere (Beverton & Holt, in press), special attention being paid to the attainment of steady-state distributions in a strictly limited area within which the distribution of food organisms and refuges was not uniform.