KNOWLEDGE BASE

By analysing fragments of tree trunks with beaver gnaw marks, scientists were able to better understand the historical range of Eurasian beavers. The fragments were found frozen in the tundra of the Yamal peninsula, a part of Russia inside the Arctic circle. As the climate changed during the Holocene period, the forests in this area expanded and retracted. So too did beavers' range, with their range's northern boundary only stabilising in the Late Holocene as the forest-tundra zone’s southern boundary became fixed. Please note, this resource is not open-access.

In the Netherlands, dead Eurasian beavers were tested for pathogens to understand their potential relevance to public health. Three types of pathogen were detected, suggesting that, whilst beavers can certainly host zoonotic diseases, their role in spreading these pathogens was limited in the Netherlands. Please note, this resource is not open-access.

With beaver populations in North America having declined by up to 98%, so too had beaver dams been lost, along with their effects on water storage and sediment retention in the landscape. In Colorado, USA, scientists used a computer model to analyse these impacts, and the extent to which suitable beaver habitat had also been lost. Implications and approaches to restoring beavers and beaver wetlands were discussed in the last sections of the article.

Beavers in Europe have been recovering from a dramatic population bottleneck. However, the complex mix of translocations and natural population expansion had made understanding the ancestry of different populations challenging. This study investigated the ancestry of newly-established Eurasian beaver populations using various genetic analyses including that of microsatellite genotypes - a first for Eurasian beavers. The results showed that, whilst relict populations had very low genetic diversity, translocated populations had much higher diversity. The exercise also showed that specific genetic markers such as microsatellite genotypes can helpful with understanding the ancestry of recently-separated populations.

In this text, researchers analyse perspectives held by humans downstream of a site where beavers have been introduced to help with managing flood risk in England. The results describe a variety of feelings and narratives, ranging from concern to excitement, and relating to different aspects of the reintroduction. The text emphasises the need to understand diverse community perspectives in beaver reintroductions and advocates for specific areas of research relating to peoples' concerns.