Search Results

The purpose of this research was to assess whether there is an integrated approach to providing both turtle passage and beaver exclusion from drainage culverts on highways managed by the Ministry of Transportation.

The goal of this project is to test whether a restoration method developed and tested in Bridge Creek, Oregon will be suitable for restoring streams like Pataha Creek in southeast Washington.

Tested how assisting beaver to create stable colonies and aggrade incised reaches of Bridge Creek could create measurable improvements in riparian and stream habitat conditions and abundance of native steelhead.

Ecosystem engineers, such as the Eurasian beaver, Castor fiber, transform habitats, thereby creating favourable conditions for other species and increasing biodiversity. Multiple studies have revealed that beaver ponds are valuable habitats for invertebrates and vertebrates, including other mammals, but the impact of watercourse damming on the fauna of small terrestrial rodents and shrews has not yet been documented. We aimed at testing the hypothesis that the presence of beaver dams and consequent flooding enriches the small mammal assemblage both quantitatively and qualitatively. We live-trapped small mammals at nine beaver-modified sites on 300 metre transects alongside dammed watercourses, starting from the dam through to the pond to the sections with unmodified lotic conditions. The abundance and species richness of trapped small mammals were highest near the dams and declined with distance. Additionally, five out of 12 trapped species significantly decreased their abundance with distance from the dam and none revealed the opposite trend. Four species were more abundant on plots subjected to damming (especially Sorex minutus and Micromys minutus), while none were present solely on undammed plots. Among the semi-aquatic species, two water shrews benefited from beavers’ activity in different ways. Neomys milleri occurred only in flooded sections, while N. fodiens preferred unmodified sections, but was the most numerous closer to the dams, following the already known patterns of competitive displacement observed in Central Europe. An important factor affecting small mammals, the herbaceous layer cover, appeared to be interdependent with damming. We provide the first unequivocal evidence that beaver dams facilitate the abundance and diversity of small mammals, presumably due to increased food abundance, availability of shelters and habitat connectivity. Beaver-created wetlands may act as potential refuges for the species most susceptible to the consequences of anthropogenic climate change, while revealing a critically low range-shift capacity.

A current challenge in ecohydrology is the incorporation of beaver dams into hydrological models. Select works have attempted to solve this problem using routing approaches, Manning coefficient variations, pond dynamics, or fully-distributed hydraulic models; however, all these approaches assume that all beaver dams are homogeneous structures and react in the same way to rainfall events. Recent findings highlight the importance of including the functional heterogeneity of beaver dams, especially the water path past the dam (dam flow state). To overcome the challenge of accounting for different dam flow states interrupting downstream water transmission in different ways, we developed BEAVERPY, a flow state-based Python package that can be coupled with the platform Cold Regions Hydrological Model (CRHM) to represent both streamflow modulation by ponds and dams, while also simulating infiltration and evapotranspiration. We used the broad-crested weir equation for the overflow dams, the Darcy equation for the seep flow dams, and the v-notch weir equation for the gapflow dams, verifying each case with synthetic experiments. To calibrate and validate the model, we instrumented the ponds and streams in a peatland fen in the Canadian Rocky Mountains in Alberta with level sensors and ‘DamCams’ (trail cameras) to capture flow type. Then, we used LIDAR DEM data and high-resolution imagery to delineate the hydrological response units. Each pond is represented as an HRU, which can interact with soil and routing modules. Finally, we conducted a scenario-testing experiment to understand the sensitivity of different beaver dam flow states for several storms. The results indicate the importance of including flow state dynamics for the beaver dam representations, and highlight the importance of integrating animal-ecological aspects into the streamflow modelling. This research has implications for understanding the use of  beaver as a nature-based solution for flood mitigation and river restoration.

The aim of this paper was to test whether the space use of Eurasian beavers seasonally varies and whether the pattern comprises diverse habitats.

Study that tested whether beavers are energy maximizers by verifying the prediction that they allocate time to foraging activities independently of habitat quality in Kouchibouguac National Park of Canada in New Brunswick.

Testing the hypothesis that controlled floods intended to drive the fluvial geomorphic and hydrologic processes necessary
for native tree recruitment will simultaneously destroy beaver dams.

Study to gather and produce human dimensions-inclusive, basin-centralized beaver knowledge through an explorative, benefits-maximizing approach to landscape-scale BAR opportunities assessment in the Salinas River.

This study by the Oregon DFW and the OWEB used surveys to examine OR residents opinions about beavers.

This thesis provides a Beaver Dam Surface Water Estimation Algorithm, a model that takes observation data of 500 beaver dams to quantify the distribution of dam sizes, then using that data to develop a model for predicting water storage. While the water storage provided by beaver dams is only a small fraction of expected snow water equivalent loss, it is not insubstantial and may prove beneficial for ecosystems where human-made reservoirs are not available to regulate hydrologic regimes.

This guidebook provides a practical synthesis of the best available science for using beaver to improve ecosystem functions. The overall goal is to provide an accessible, useful resource for those involved in using beaver to restore streams, floodplains, wetlands, and riparian ecosystems.

This study evaluated habitat selection by European beaver across a spatial gradient from local (within the family territory) to a broad, ecoregional scale. Using aerial photography, the researchers assessed the habitat composition of 150 beaver territories and compared these data with 183 randomly selected sites not occupied by the species.

Researchers examined interactions between beaver and fish communities in the types of streams selected for Eurasian beaver re-colonization. They found several critical elements of fish communities in these mountain streams that relate to beaver activity and its effects.

We used a spatial survey of fish assemblage structure in streams and beaver ponds to: (1) determine the effects of beavers on fish assemblage structure at the reach and drainage basin scales, and (2) assess the influences of pond age, watershed position, and pond environment on fish assemblage structure within beaver ponds.

We have developed and implemented a simple approach that emulates the ecosystem engineering effects of beaver. This approach is less expensive and disruptive than typical large-scale engineering efforts and has the potential to restore both fish habitat and floodplain vegetation more rapidly than simply revegetating and waiting for the riparian zone to mature.  (Pg 246 – 255)

Dam building by beaver in degraded environments can improve physical and biological diversity
when viewed at a scale encompassing both modified and unmodified habitats.

I. Schlosser performed a long-term study to analyze changes to species density, fish predation, and precipitation over time in beaver ponds and their associated streams. In addition to an experiment that looked at the effects of these temporal changes on invertebrates. Yearly, there were significant variations in the amount of precipitation. The researcher suggests that dispersal is a significant factor in determining fish density and diversity, as well as effects of their predation on invertebrates.

Research and monitoring activities over a 45-year period on the Quabbin Reservation in Massachusetts have provided an opportunity to follow changes in numbers and dynamics of an unexploited beaver population.