The Price and San Rafael rivers flow through some of Utah’s driest areas. Both are tributaries of the Green River. These rivers are essential to sustain the wildlife, riparian vegetation, native and endangered fish populations, and livestock that live in Utah’s eastern desert.
Beavers, native to both rivers, have far-reaching impacts on these waterways because of their ability to build dams that hold the water on the arid landscape – they are nature’s aquatic engineers.
One beaver dam can improve the living conditions for a host of fish, insects, plants, birds, and mammals who live in and around the river.
Emma Doden, a graduate student in the Department of Wildland Resources in the Quinney College of Natural Resources at USU, is working to understand the dynamics of beavers who are translocated to desert rivers for restoration purposes and how they compare to the naturally-occurring resident beavers who are already established.
Doden explains, “I help relocate nuisance beavers to desert river systems to give them a second chance, and help restore the river for the imperiled and endangered fish species…in this arid climate.”
Currently, Doden’s work is “passive desert river restoration” because there is no machinery manipulating the landscape or man-made structures impacting the research results. She is relying solely on beavers and their resources which have been part of the rivers’ ecosystems for millions of years. The beavers’ engineering teeth, tails, and paws build dams and lodges from riparian vegetation, gravel, and mud.
Many of the translocated beavers come from the USU Beaver Rehabilitation and Relocation Center which captures nuisance beavers, quarantines them for three days to ensure they cannot spread disease, then passes them to Doden to be released in the desert system.
Nate Norman, a field biologist in the USU Ecology Center who helps operate the Beaver Rehabilitation and Relocation Center said, “working with Paul Chase from the US Forest Service we have trapped and relocated approximately 8 to 10 beavers from around Cache Valley (in northern Utah,) to the desert rivers in Doden’s research.”
Both the resident and translocated beavers in the study receive a radio-transmitter and PIT-tag in their tail.
Doden explains, “the PIT-tag is similar to the microchip (a) dog or cat gets at the vet for identification if it ever gets lost. We use radio-transmitters and PIT-tags to track the movements of our beavers so they do not become lost after release.”
To this point, 90% of the translocated beavers have moved outside Doden’s research area as they explored their new habitat. They were probably searching for a companion and a suitable place to build a home.
This traveling increases the beaver’s vulnerability to predators since they have no underground burrow or lodge for protection. During the 2019 field season, of the eight beavers released, three of the translocated beavers were taken by predators.
Many of the tributaries of the Green and Colorado rivers are wood-deprived because of changes in the river flow due to human extraction. To increase a translocated beaver’s chances of surviving and its likelihood of remaining where it’s placed, the research team has proposed building simple dam-like structures out of wood fence posts, which would encourage the beavers to stay where they’re released. Once they receive NEPA approval the structures will be built.
Doden adds, “Our project goals are already being met, as we are learning so much about the fate of translocated beavers in desert ecosystems. Restoration goals will also be met if even a few beavers stay in the study area and build dams, supplementing the resident beaver population and creating more complex habitat for imperiled desert fish to live.”
Sound credit for this piece: Friend Weller