KNOWLEDGE BASE

Wolves in Poland eat different things depending on what region they live in. Beavers were a significant prey in northeastern Poland, but less so elsewhere. The scientists suggested that this difference between wolf populations was influenced by prey availability and habitat specialisations, rather than, for example, wolf populations being separated from each other geographically.

Seven North American beavers were brought to Finland in 1937 to boost the dwindling population of Eurasian beavers. Later, it was discovered they were different species. Now, both species are spreading in Finland and Russia, raising concerns about competition between the species. Research shows they share similar habits and may compete for resources, potentially leading to the local extinction of Eurasian beavers. To prevent this outcome, pillars of an eradication plan are described.

This article responds to a previous paper suggesting three options for reintroducing Eurasian beavers in Britain and Western Europe: using beavers from one western population, mixing beavers from multiple western populations, or mixing eastern and western beavers. The authors suggest that, since option three goes against international conservation guidelines, options one and two should be the focus. They emphasise the importance of further genetic analysis and suggest that decisions shouldn't be based solely on cost or the genetics of existing captive and escaped populations.

Climate change affects not only average weather but also its variability. This study compared climate trends over 90 years and compared it to beavers' survival at different ages. Overall, beaver survival was linked to less variable precipitation and temperature. These findings highlight the importance of environmental variability - as one of the impacts of climate change - in regulating populations, even for a species as adaptable and long-lived as a beaver.

Beavers were reintroduced to Eagle Creek, USA, in 1991 to help with the recovery of aspen trees. This study reports on 15 years of monitoring: where aspen trees were found as well as how tall and how old they were. Overall, the study found that, while beavers stimulated aspen sprouts and saplings, browsing by deer, elk, and bison hindered successful aspen recovery. Please note, this resource is not open-access.