KNOWLEDGE BASE

The Eurasian beaver population in Europe is rapidly growing due to reintroductions and natural expansion. Population-level data gets quickly outdated. Collected in 2019, this study estimates there are nearly 1,222,000 beavers in Europe.

When researchers try to predict where beavers may settle, they often relied on information from fully-established colonies, potentially misidentifying suitable sites for establishing a colony. In the USA, scientists analysed new beaver colony locations and found they preferred areas with low gradients, narrow channels, high canopy cover, and nearby low-lying areas. Adding artificial beaver structures can encourage beavers to settle in a specific place, too.

This article recounted the history of beavers in Italy. It says that humans likely played a significant role in making beavers extinct in Italy around the 16th and 17th century, but through altering habitat more than hunting. Beavers have likely never lived in southern Italy. The article includes maps of where beaver remains have been found in Italy and some images of beavers from medieval Italian texts.

Beaver ponds host unique biodiversity which is different from that found in other landscapes. Restoring beavers to their native habitats can enhance freshwater biodiversity, but beavers alone won't solve freshwater biodiversity issues. This study is based on a survey of plants and beetles in southern Sweden.

In this study, scientists tested otters, raccoons, and beavers for the presence of mercury and other chemicals. It found that mercury was more concentrated in otters (who eat fish) than beavers (who eat plants). The results also suggested a possible connection between higher mercury levels and a higher quantity of parasites. Overall, this study demonstrated the threat of human pollution to ecosystem health. Please note, this resource is not open-access.