KNOWLEDGE BASE

This study followed wood frogs and spotted salamanders in ponds across three states of the USA. Beaver activity created new ponds, enabling both species to move between ponds. The scientists undertook a detailed analysis of how connected the different populations were, aiming to improve amphibian population monitoring programmes, a key part of conservation 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.

Researchers studied beavers' eating preferences in Canada to test a theory called 'central place foraging theory'. Researchers assessed food availability near 25 beaver groups and found that in places where there was more food available, beavers were more selective: they cut fewer, larger trees. This confirmed the predictions of central place foraging theory.