KNOWLEDGE BASE

The mammal population in the British Isles has changed a lot since the last ice age. 19 species have disappeared and 22 non-native species have been introduced. This has affected the balance of ecosystems, with species like rabbits and red deer becoming very common. Beavers show how reintroductions of animals are possible, but it's hard to predict how they'll affect the ecosystem. This article presents a simulation to suggest that reintroducing wolves to Scotland wouldn't significantly impact the high-density deer populations. Please note, this resource is not open-access.

This study explored how hunting male beavers affects reproduction in beavers. The results show that 'harvesting' of male beavers disrupted beavers' reproductive cycle, leading to kits being born later. Being born late reduces the chance of kits' survival. This means that hunting of male beavers affects overall population health - this is a particularly drastic effect because beavers are monogamous.

This text explores how fishes are distributed in streams. It questions the traditional idea of species richness increasing as you go downstream - which is based on evidence from only one type of fish - and suggests an alternative model. It tests this alternative model using a stream in Canada. The findings are that the presence of Atlantic salmon, beaver dams, and water flow levels also influence the fish community. This challenges the previous understanding of fish distribution in streams.

This study preceded beavers' more widespread reintroduction to Britain. Using questionnaires and economic tools, it estimated the economic pros and cons of beaver reintroduction, trying to put a number on the boost to wildlife tourism and the cost of their damages. The results showed that the economic benefits would likely far outweigh the costs.

The Central European highlands have few areas of still water. Here, in Germany, beaver ponds were shown to provide essential habitat for a whole range of amphibian species. Benefiting both common and rare amphibians, the diverse habitats created by beavers provided protection from predators. The authors explained how the near-extinction of beavers in Europe needed to be considered when trying to understand the distribution of amphibian species today, as well as planning for amphibian species conservation in the future.