KNOWLEDGE BASE

This study looked at how the nutrients provided by the dying parent generation of coho salmon affect young coho salmon in Alaska. They compared fish in three types of beaver pond: those downstream of spawning areas, those not affected by spawning salmon, and those not naturally affected but artificially enriched with salmon carcasses and eggs. The extra nutrients boosted growth rates and condition in some ponds but didn't consistently lead to better survival. This suggests that the nutrient cycle between generations is likely to be more complicated than initially thought.

In this article, researchers tested the accuracy of their methods for counting Eurasian beavers. This is something which was often poorly reported on in beaver science. They found that counts of beavers varied quite considerably according to time of day and even the month of the year. Repeating their counts led to new information which allowed them to adjust their overall estimate of family size. Kits were often undercounted.

In this article, researchers compare the impacts of two types of bullet for shooting beavers. These impacts included the damage to the beavers skin and the amount of meat lost in the process. They also estimated that 98% of the beavers in this study died instantly.

In 2001, tail-mounted transmitters were attached to 41 beavers in the USA. Most fell off and some were lost inside lodges. Some of the transmitters that had fallen off were found intact but many had missing antennas, likely chewed off. Overall, tail-mounted transmitters were of limited success in this study and are not recommended for long-term monitoring without significant modifications to the original design. Please note, this resource is not open-access.

This study looked at how beaver dams and meanders affected the interaction of stream water with sediment below the stream. The area of study - in the USA - was pretty dry, meaning that beaver wetlands are uncommon, but dams still exist. This water-sediment interaction is important for trapping nutrients and pollutants, especially in areas damaged by livestock. The researchers found that beaver dams and meanders enhance this interaction. However, in some reaches of the stream, the trapping of sediment was longer-term than in others. Please note, this resource is not open access.