COMEBACK OF THE BEAVER CASTOR FIBER - AN OVERVIEW OF OLD AND NEW CONSERVATION PROBLEMS

Due to over-hunting c. 1200 Eurasian beavers Castor fiber survived in eight relict populations in Europe and Asia at the beginning of the 20 th century. Following hunting restrictions and translocation programme s in IS countries, the Eurasian beaver became re-established over much of its former range, and presently numbers c. 430 000. The translocat ed populations often consist of a mixture of geographical forms. Prese rvation of the original, unmixed populations has therefore top priorit y. all five in Europe have reached the assumed minimum viable populati on size of c. 1880 animals each, but the three in Asia are still endan gered. Their protection should be carried out at the level of river ca tchments. Nowadays the main threats for beavers are habitat destructio n and introduced North American beavers Castor canadensis. On the othe r hand, gr owing beaver populations cause increasing conflicts with ma n, and population and/or damage control may therefore be required. In view of these two very different problems, we conclude that the conser vation of beavers is best served by preservation and restoration of ri parian woods with intact natural water regimes. (C) 1998 Elsevier Scie nce Ltd.