KNOWLEDGE BASE

In mammals, the uterus usually degenerates as the male foetus develops but, in some male Eurasian beavers, the leftover structure - called the uterus masculinus - can be quite large! This does not affect reproductive ability. This paper investigated the hormones present in this organ, finding lower levels of progesterone and estradiol compared to the female beaver's uterus. The uterus masculinus has also been reported in other animals, so these findings could help contribute to our understanding of gender identities and reproductive health issues. Please note, this resource is not open-access.

This thesis described the first ever investigation of how Eurasian beavers' dams affect brown trout in a British context. Results showed that, in this area of Scotland, a beaver-modified stream supported larger trout with more diverse ages compared to a control stream without beavers. Beaver dams did not hinder fish passage when there was lots of water but may cause delays in times of low flow. The study also highlighted how beaver dams can change the distribution of predators - in this case, the heron.

Researchers characterised the soil moisture and plant communities present in the beaver meadows of the Ablánc stream, Hungary. The results showed that the beavers' dams created conditions of permanent flooding and, so, very high soil moisture levels, supporting the presence of various water-dependent plant species. This demonstrated beavers' ecosystem engineering capabilities.

In this paper, researchers used bibliometric analysis to examine the existing body of research relating to beavers. The researchers identified a skew towards research in the USA, UK, and Canada, and a growing interest in research relating to beaver population dynamics. However, only a small portion of studies explicitly focused on beaver-related ecosystem restoration. The review made recommendations of what research was needed to guide conservation and restoration efforts going forward, suggesting that holistic "socio-ecological management models" were needed, including early public engagement.

In Poland, researchers sought to work out how Eurasian beavers feel about urban environments. They found that, at a landscape scale, Eurasian beavers generally prefer to avoid such areas. However, 13% of the beaver sites they studied were in the most densely-populated regions, so beavers can clearly adapt to the relatively small patches of habitat present in urban environments. As beavers continue to expand across Europe, the authors suggested that studies like this will be important to understand and manage potential human-beaver conflicts in urban areas. Please note, this resource is not open-access.