KNOWLEDGE BASE

In this study, researchers established that the disappearance of beaver ponds has drastically reduced the habitat for coho salmon in a river basin in the USA. They estimated that loss of beaver ponds was the primary cause of summer habitat reducing by 61% and winter habitat by 86%. The study suggests that restoring beaver populations should be part of river restoration efforts.

After 15 years of study, this paper summarises the available evidence on the introduction of the North American beaver to Argentina in 1946. Without predators, population and habitat had rapidly expanded, from 25 pairs to tens of thousands. The paper describes beavers' impact on nutrient cycles and on landscapes as well as their habitat preferences and genetic structure. For example, these beavers show a preference for inhabiting streams on shallower slopes.

This study analyses the genetic structure of 50 European beavers in a Russian river basin. Genetic diversity was higher when comparing colonies and lower when comparing groups across tributaries. The factors contributing to this pattern are discussed, along with the implications. By calculating an indicator called the effective reproductive size, the author is able to explain why beavers are resistant to inbreeding and have been able to recover so well from near-extinction conditions. Please note, this resource is not open-access.

This article describes the first known case of a Eurasian Beaver dying due to a collapsing burrow. The collapse was attributed to heavy rainfall and sandy soil. It was an adult male who had been radio tagged and had no external injuries.

This study explored whether, and how, Scandinavian beavers distinguish between subspecies. Beavers were found to react more to castoreum scents than anal gland secretions. They found that beavers responded more to scents from their own subspecies, suggesting they can distinguish between them. This ability likely developed due to geographic isolation.