KNOWLEDGE BASE

This paper seeks to set out the cumulative effects of the decline in beaver populations across the Northern Hemisphere on the functioning of streams. They present evidence that fewer beavers has meant more soil erosion (affecting valley shape) and less fish habitat (affecting fish populations).

This paper describes three newly-classified species of fungi in the USA. These fungi grow in the resin of conifer trees which collects in the scars created by beavers. One of the species of fungi is also found in Northern Europe.

The classification of Eurasian beavers (Castor fiber) into subspecies has been muddled due to inconsistencies in following naming rules. This has led to confusion both in nomenclature and taxonomy and may limit the chances of successful reintroductions. This paper explores this history and concludes by recognising and listing nine subspecies of the Eurasian beaver: C. f. fiber, C. f. galliae, C. f. albicus, C. f. vistulanus, C. f. pohlei, C. f. birulai, C. f. tuvinicus, C. f. belorussicus, and C. f. orientoeuropaeus.

This study recounted the fates of different mammal and bird species over four centuries of life in Massachusetts, USA. It combined a variety of data sources to do so, and identified six key population trends. Beavers, along with other species such as the white-tailed deer, showed the 'decline and recovery' trend - decreasing early on in the historical period but recently rebounding rapidly. The authors noted that rapid wildlife changes pose conservation challenges, including potential conflicts with human populations.

After near-extinction, beaver populations in Eurasia were recovering quickly around the turn of the millenium. In this text, the authors described the typical patterns of beaver recolonisation. They recommended that management should focus on a watershed scale, adjusting for big physical barriers like man-made dams. They also suggested that regulated hunting and pro-active public communications were advisable for sustainable management and for mitigating human-beaver conflict.