Patterns of spread of a reintroduced beaver Castor fiber population in Sweden

Abstract

On the basis of questionnaires to moose hunters the colonisation pattern of reintroduced beaver in the province of Värmland was mapped. The beaver spread rapidly within water drainage systems resulting initially in scattered colonisation and very low population densities in relation to range. Spread was slowed by watershed divides. Illustrating the shape of the expansion wave front by plotting the relative increase of the population and range against time, shows a very flat front characterised by long dispersal distances.