Modelling territorial behaviour of animals in variable environments

We present an. individual-based model describing the distribution and resou rce gain of territorial individuals in situations where the rank order of t erritory quality changes over time. The model integrates both competitive ( territory-holding ability) asymmetries and a memory function. A balance of effects resulted in a peak in movement rates, but not resource gain, for in dividuals of intermediate ability. Furthermore, when the system was reduced to a linear array of territories (as commonly used in empirical studies) t he model generated quite different predictions because of the severe limita tion in movement that the linear array imposes. We suggest that the model c an be used to generate testable predictions for territorial species such as salmonids, and that future empirical work should take into account the con sequences of reductions in movement imposed by a linear array of territorie s. (C) 1999 The Association for the Stud of Animal Behaviour.