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.

Scientists in Hungary identified a new polyomavirus (PyV) in two Eurasian beavers, marking the first global discovery of PyV in these animals. This virus was likely a new species, although further research was needed to understand its impact on beaver health. Please note, this resource is not open-access.

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.

For this study, scientists compared two beaver populations: one which was introduced 42 years ago, and another which had been around for 72 years. By comparing them, scientists hoped to learn about beavers' foraging strategies and impacts on tree biodiversity. Whilst the older population moved further away from the water's edge to find food than the younger population, both were assessed to be following 'Optimal Foraging Theory.'