a1 Penwith Sixth Form College, St Clare, Penzance, Cornwall, TR18 2SA
a2 Department of Biological Sciences, Polytechnic South West, Drake Circus, Plymouth, PL4 8AA
Dispersion in a littoral population of Pagurus bernhardus in south-west England is shown to be random, with members demonstrating no evidence of site attachment. Movement patterns within the population are shown to be asynchronous and random, and to be dictated by the quantity and quality of each individual's shell contacts. These, in turn, affect the time that individuals spend within the habitat. This implies that population dynamics and residence times are so influenced by the availability of suitable empty gastropod shells that movement and migration in hermit crabs should be regarded as resource-dependent phenomena.