KNOWLEDGE BASE

This article reviews the emerging field of reintroduction biology. It looked at 454 papers from 1990–2005 and found that most research on wildlife reintroductions was retrospective and opportunistic. Whilst documentation of outcomes had improved, there was potential to use experimental and modelling approaches to enhance success. The case of beaver reintroductions to Scotland and the Netherlands were given as positive examples of using modelling approaches to assess reintroduction viability.

In this article, researchers report on an analysis of over 430 otter faecal samples. They detected two types of parasite linked to water contamination and public health risks. Discussing these results, the authors note that beavers have been the likely source of several disease outbreaks linked to the Giardia parasite in North America. Please note, this resource is not open-access.

This experiment tested how beavers' eating patterns affect freshwater plants. Researchers compared, over a period of 2 years, a beaver wetland to a wetland to which beavers were not allowed access. Beaver presence led to a 60% reduction in aquatic plant biomass, including a large reduction in an invasive species. It was shown that woolgrass tussocks were good at protecting certain species from beavers: acting like natural cages. Overall, this shows that beavers affect the aquatic floral ecosystem in ways that extend beyond just their engineering behaviour.

Today's land managers face challenges like fire, drought, and climate change. Balancing these requires understanding how they interact. While prescribed fires are used for ecological restoration, their impact on beavers isn't well-understood. In Elk Island National Park, Canada, researchers studied how prescribed fires affect beaver lodges. Repeated fires reduced beaver presence and beaver habitat. More research is called for to be able to effectively manage this ecosystem. Please note, this resource is not open-access.

This report assessed the status of beaver populations in the Rocky Mountains, USA. Despite the pressure of habitat destruction, populations appeared to be stable or growing. Improved trapping regulations, habitat protection, and population restoration efforts had helped. The report acknowledges the damage that beavers can cause in some areas, but says that their presence is usually desirable because of their ability to maintain healthy ecosystems. The report says that conservation efforts should focus on protecting habitats and pro-actively managing any damage issues and human conflicts.