KNOWLEDGE BASE

A novel polyomavirus, Alphapolyomavirus castoris, had recently been identified in the kidneys of healthy Eurasian beavers in Hungary. This text presented the genome of this virus, showing that it was genetically very different from other polyomaviruses. The virus, although unlikely to cause illness alone, may enable other pathogens to cause illness. The authors suggested that, given the lack of research and their aquatic lifestyle, beavers may harbour more undiscovered viruses.

Monogamy is common in birds but less common in mammals. In addition, research has found that social monogamy does not necessarily imply genetic monogamy; that is to say, intercourse (and paternity) with individuals from outside the couple can often occur. This is called 'multiple paternity'. Both species of beaver are traditionally considered to be both socially and genetically monogamous, but is that really true? This study tested this theory in an Austrian population of Eurasian beavers. It found that 5% of the litters tested showed multiple paternity, and discussed what drivers may explain this behaviour.

Previous research had shown that beaver-modified ecosystems can support more bats, but the mechanism by which they do so had not been tested. Analysing data from the River Otter Beaver Trial in Devon, England, this article showed that beaver sites significantly increased the abundance and diversity of aquatic invertebrate species: these are key prey for bats. Bat activity was significantly higher at beaver-modified sites, too, suggesting that beaver reintroduction benefits bats by improving the availability of their insect prey.

After being reintroduced to northern Croatia, beavers spread along streams to new parts of the country. This paper presented evidence, including photos in Figure 2, of beaver activity in a cave in central Croatia. Researchers suggested that limited surface habitats and human pressures may have driven beavers to use the cave, likely accessing it through an underwater entrance. The finding posed many additional fascinating questions which, although discussed in the text, would need further research to be answered definitively.

36 urban wildlife experts in Germany were interviewed to understand how to manage human-wildlife conflicts in cities. The key species causing issues were foxes, wild boars, raccoons, martens, and beavers. This article contained an analysis of these conflicts, and compiled a toolkit for managing such conflicts. Within this toolkit, actions such as public education, urban planning integration, and stricter enforcement of regulations were mentioned. For beavers, adaptations of urban green spaces were highlighted.