DESCRIPTION
The Washington State Department of Fish and Wildlife and partners set out to increase stream complexity and riparian system function by live trapping “problem beavers” from urban and agricultural areas in the Yakima Basin, where they were being lethally removed. Instead, the beavers were strategically relocated in priority upper Yakima River tributaries (NF, MF, WF, Teanaway; Bear Creek; Standup Creek; Jungle Creek; Jack Creek; Indian Creek; Rye Creek; Robinson Creek; NF Manastash; Taneum; Swauk Creek; Hurley Creek; Hovey Creek; Williams Creek; Umtanum Creek; Willow Gulch; Cougar Gulch; Lion Gulch; Blue Creek). These relocations were aimed to improve fish habitat and restore riparian function, water quality and hydrograph function.
Beaver are a keystone species, creating habitat and influencing natural processes that many other species depend upon. For instance, Coho that rear in beaver ponds have substantially better fitness and survival. Beavers were historically very numerous in the watersheds on the east slopes of the Cascade Mountains. Early trapping efforts by the Hudson Bay Company and others dramatically reduced beaver numbers in these watersheds. There has been a continued cultural intolerance of beavers near development. Beaver removal has reduced beaver populations and dramatically altered tributary watersheds. The USGS reports that the upper Yakima River hydrograph has shifted ~3-4 weeks earlier over the past 30 years, likely as a result of climate change. Restoring beavers in the upper watersheds will help counter this trend and provide better late season flows for fish passage, as well as improve fish habitat and water quality.
This project supported 134 land owners with nuisance beavers. Our staff provided support to landowners who were receptive to managing beavers in place. Dozens of trees were fenced or painted to deter beavers, 2 beaver deceivers were installed around culverts, and 2 pond levelers were installed to control pond height.
Our staff set live traps and snares when management in place was not a valid option. We were able to trap 140 nuisance beavers. Four beavers died in captivity, 4 escaped our holding pens, 2 kits were returned to their colony, 2 beavers had a late season relocation, and 128 beavers were relocated to headwater systems. Two of the relocated beavers were found dead (one by predation and one by gunshot wound). Twelve of the 34 colonies reintroduced were successful. A successful reintroduction by our definition is a beaver colony that remains in place one breeding year with beaver built infrastructure in place. Of the beaver colonies that were not deemed successful, 14 beavers were located traveling through PIT tag arrays suggesting they are persisting elsewhere in the watershed. This project has worked very closely with other beaver introduction projects, sharing lessons learned and adding to the collective knowledge in using beaver reintroduction for salmon recovery.