KNOWLEDGE BASE

This study looked at how wolves, beavers, plants, and other species are connected and affect each other in Yellowstone National Park, USA. The findings showed that the risk of predation by species like wolves profoundly affects ecosystem structure. Wolf reintroduction helped improve access to willow trees for beavers to eat. Understanding these processes can help improve ecosystem 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 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 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.

In the USA, a complex of several small beaver ponds was destroyed for construction and some new wetlands were built to replace it. Despite meeting regulations, this study shows that the replacement wetlands didn't fully restore the original ecosystem. Fish populations decreased, with fewer native species and a disproportionate negative impact on species which prefer flowing water as a habitat. Researchers used the Index of Biotic Integrity (IBI) as a tool to understand this change. Please note, this resource is not open-access.