KNOWLEDGE BASE

Animals were once considered to have relatively minor impacts on the shape of the land around them. This book described how, in fact, animals can play a significant role, whether they are invertebrates, vertebrates, birds, or mammals. Behaviours like burrowing, trampling, nesting can all contribute. The book contained a chapter on beavers' contributions to shaping the land, particularly through the construction of dams. Please note, this resource is not open-access.

In this paper, 10-years of observational data were combined with learnings from an in-river experiment to better understand how beaver ponds affect fish in nearby streams. The paper describes their impact in detail, but suffice to say that beaver ponds play an important role in shaping fish lifecycles. In contrast, conceptual models of fish ecology in this part of the USA, at the time of publication, did not really consider beavers due to them being absent from the area due to historic over-hunting.

Fossil remains of a beaver-like species Steneofiber, now extinct, were found in a quarry in France, revealing a family group with two adults and eight juveniles. The fossils revealed many interested insights, including a "K-strategy" reproductive pattern similar to modern beavers, and a "combing-claw" which modern beavers use to comb their fur - an adaptation for semiaquatic life. The Steneofiber beaver's tail was likely cylindrical, however, in contrast to modern beavers' flat tails.

A study of 273 wild mammals in the USA found that 24% had antibodies to a parasite called Toxoplasma gondii. Several beavers tested positive, although beavers did not show the highest prevalence of the parasite. This article reported on the methods followed, including whether or not Toxoplasma gondii was successfully isolated from the mammals.

Researchers sought to understand why willow trees had declined in northern Yellowstone, USA. They identified that several factors had contributed to this, including the decline of beavers. Without beavers, the water table had reduced in different places, creating a drier habitat less suitable for willow.