KNOWLEDGE BASE

The return of beavers to a National Park in the USA has led to an 89% increase in wetland habitats between 1944 and 1997. Beavers had converted forested areas to open water and wetlands, benefiting pond-breeding amphibians by providing more breeding sites. Beavers initially favoured larger, lower sites, but later on, beaver sites were smaller and higher up the river. Many were abandoned, creating a diverse habitat mosaic. Please note, this resource is not open-access.

One challenge of managing conflicts between humans and beavers is the fact that people's views vary and change over time. In the USA, after a law was passed banning certain beaver traps, surveys were carried out to understand public opinion. This article reports on these surveys. Overall, people had positive views of beavers but those who had had negative experiences with beavers held less favourable views. The authors suggest that conservation efforts should be responsive to changing public attitudes. Please note, this resource is not open-access.

This study tested the impact of Eurasian beavers browsing on willow plants in winter. They simulated beaver browsing by pruning willow shrubs in February and comparing the shoots with those of shrubs that had not been pruned. The new shoots were tested in May and November. In May, pruned shoots were more nutritious and were preferred by beavers. In November, there was no difference in nutrition nor in beaver preference. This suggests that, after browsing, willows prioritise regrowth rather than any type of defense mechanism.

Fossil remains of beavers were found in lignite sediments in Italy, dating back around 3 million years. Based on analyses of the beavers' teeth, researchers had been debating what species of beaver these remains belonged to. This study compared these fossils with others and also modern Eurasian beaver populations. The results suggested that the fossils belonged to a different subspecies to modern Eurasian beaver populations. Please note, this resource is not open-access.

Mammals use scent to mark their territory but this can attract predators. In this experiment, scientists looked at how beavers reacted to intruders, by planting scents of predator and non-predator animals. They found that both predator and non-predator scents reduced beavers' scent-marking activity but the predator scent had a stronger effect. This suggests beavers living in territories with predators may be more vulnerable as there is a trade-off between avoiding predators and defending territory.