Forage Preferences of the European Beaver Castor fiber: Implications for Re-introduction

Abstract

By the beginning of the twentieth century, hunting and land use change had reduced the European beaver Castor fiber to a relict population of no more than 1200 individuals. In some European states, re­introduction has successfully established viable populations, whilst other schemes have failed. Environ­mental, social and economic issues associated with beaver re-introduction have given rise to a range of information needs in relation to the species' ecology. In 2005, six European beavers were translocated from Bavaria to a re-introduction site in southern England. The following year, a 6 month study was un­dertaken to investigate which tree species and size classes were most frequently utilised by the beavers, and to determine if the utilised species and size classes reflected resource availability within the home range. These questions were answered by comparing the use and the availability of foraged tree species in two ways: (1) using a survey of tree stumps; and (2) as a food choice experiment. The results showed that the re-introduced beavers were highly selective in relation to both the species and the size of the trees they used i.e. the re-introduced beavers selected species in significantly different proportions to their availability. However, they selected similar size classes between the preferred tree species, and did not utilise human 'timber'. The relevance of the study is discussed with respect to information needs as­sociated with the re-introduction of a 'keystone' species, overcoming negative perceptions, population viability, welfare and 'soft release' strategies.