Murrelets in the project area are thought to come from nest sites in Humboldt Redwoods State Park and other pockets of residual oldgrowth in the Eel River watershed. Though murrelets often follow river valleys toward the ocean, sometimes they will jump over ridges for a distance-saving detour. Here, the concern is that murrelets from Humboldt Redwoods State Park may follow the Eel River for a time before jumping over Monument Ridge to connect with the Bear River, a more-direct flight path to the ocean.
Terra Gen, the project developer, has recognized the threat, and in response, has begun to study how murrelets use the project site—are there particular areas of high murrelet use, how high are they flying, and how many are making the trip across Monument Ridge. This information, according to Terra Gen, will inform placement of wind turbines to avoid and minimize impacts to the seabird. Using radars adapted from oceangoing vessels, Terra Gen has been scanning the skies for signs of the bird. EPIC was there to check out their survey efforts first hand.
The radar is so sensitive that skilled technicians can tell the difference in the birds that they pick up based on the shape of their radar signature and the speed of movement—murrelets, for example, need to constantly pump their wings in flight and produce a fairly large “blip” on the screen and move incredibly fast, up to 100mph.
Our tour took us to other bird survey sites throughout the project, each spaced to provide a cumulative complete look at the ridgeline, to bat survey sites, and to meteorological stations. By the time we left, the cold morning cleared to a sunny September day.
Time will tell. The full results of the survey will not be ready for two years, the standard survey protocol time, although preliminary results from the first survey year should be available earlier.