KNOWLEDGE BASE

This report summarised the evidence gathered as part of the 5-year trial which monitored wild beavers introduced to the River Otter in England. It presented a variety of evidence, including that public support for beavers was high at the beginning but had increased by the end of the trial. Some impacts on local agriculture was recorded, such as grazing on windfall apples, damaging apple trees, and eating maize. The report identifies that those who benefit from beavers' presence may not be the same people who bear the costs.

Species reintroduction can be great for biodiversity, but it has been criticised for focussing on only a few species. This paper analysed all reintroduction programs that have occurred in Europe since 1910. They found that 68% of these programmes involved only beavers, Alpine ibex, and European bison. Beavers alone accounted for almost one-third of reintroduction programs. It is possible that research and reintroduction efforts are biased towards seemingly 'charismatic' species.

This study explored how beavers influence how ecosystems recover from wildfire. By studying burned and unburned sites in the USA - some with and some without beavers - researchers found that areas below beaver dams in burned sites had better water quality than sites without beavers. Despite there having been little research conducted on this subject, these results suggested that beavers could be helpful in adapting to the climate crisis, which will bring with it more wildfires in this area.

A new breeding site for the three-toed woodpecker was found in the Sobibor Forest, Poland. This site was outside the range of the woodpecker's usual tree hosts - Norway spruce and European silver fir. Instead, the nest was in a forest of dead alders, created by flooding from beaver dams. The authors highlighted this as an example of beavers ecological role as a keystone species.

With this study, scientists aimed to better understand beavers' digestive system. Since beavers' diets change with the seasons, they killed and studied 12 male beavers in each of winter, summer, and autumn to understand how certain characteristics of the digestive system also change with the seasons. The scientists measured different features including acidity, oxygen levels, and the size of food particles, finding that many of these did vary with the season.