We’re all fortunate to live in a region that supports such diverse wildlife. And as a company, Avista understands that generating power and helping protect wildlife and their habitat goes hand in hand. One area where we’re making a significant impact is through our bald eagle management program.
Bald eagles, long revered in the U.S., were designated as our national bird in 1782 – but that doesn’t mean things were always easy for these birds of prey. Their populations plummeted in the 20th century largely due to the pesticide DDT which caused nesting bald eagles, and other birds of prey, to lay eggs with abnormally thin shells. Habitat loss and hunting added to their troubles. In 1972, DDT was banned, and in 1978, bald eagles were protected under the Endangered Species Act. Since then, populations began to recover, and fortunately, are doing quite well today.
So where does Avista fit in to all this?
Significant bald eagle habitats exist in and around our hydroelectric facilities. Avista began monitoring bald eagles as a component of the Spokane River Project license issued by the Federal Energy Regulatory Commission in 2009. Bald eagles and their nests are monitored within a half mile of waters impounded (or backed up) by the dams associated with the Spokane River Project, including the Post Falls, Upper Falls, Monroe
Street, Nine Mile and Long Lake Dams.
Monitoring helps assess if there are any impacts associated with the operation of the dams, such as shoreline erosion, which can result in loss of habitat. Other reservoir factors like recreation, shoreline development and even other competing birds can impact an eagle’s ability to nest successfully.
“This work is critical for a variety of reasons. From a compliance perspective, Avista is required to monitor bald eagles within the monitoring area to ensure our operations are not affecting the bald eagle population,” says Rob Stephens, Avista Resource Biologist. “And from an ethical perspective, it’s the right thing to do. We have a responsibility to take care of our rivers and maintain habitats for the good of the eagles and other wildlife, and for the community.”
Annual monitoring allows us to assess how many of the known bald eagle nests are active and whether their occupancy rate goes up or down over multiple years. This tells us if the population may be increasing or decreasing.
Bald eagles arrive in the Spokane River Watershed in winter around January and February. They may return to the same nest year after year and a nesting pair will defend the territory around their nest from other eagles – these are helpful traits when assessing the population status. A nesting territory is considered active if a nesting pair are observed building a nest; if an adult is observed incubating eggs in a nest; or if a nestling is observed during the months of January through July. Nests are usually close to a body of water, so most are monitored from a boat.
Every third year, Avista monitors how many nestlings survive the breeding season to become a fledging or fly from the nest, which helps determine how many bald eagles are added to the population. Every fifth year, Avista conducts an aerial survey via helicopter to locate new nests in well-concealed or limited-access locations.
Avista collaborates with the Idaho Department of Fish and Wildlife, Washington Department of Fish and Wildlife, and the United States Fish and Wildlife Service every year to review the annual monitoring results presented in our Annual Bald Eagle Monitoring Report and to assess the health of the bald eagle population.
And this important work is certainly paying off. In Avista’s monitoring area within the Spokane River watershed, territories have increased from 19 nests in 2012 to 33 nests in 2021.