Aechmophorus Grebe Monitoring & Conservation Project
Plumas Audubon Society has been monitoring western & Clark’s (Aechmophorus sp.) grebes at Lake Almanor, Lake Davis, Antelope Lake, and Eagle Lake since 2010, maintaining the most consistent and extensive dataset on the population dynamics of the two species.
Surveys are conducted at each lake throughout the breeding season (June through September). The data we collect provides insights into their nesting habitat and reproductive success.
Aechmophorus grebes are colonial breeding waterfowl species that nest on large freshwater and brackish wetlands, lakes, and reservoirs. Colony site selection is influenced by prey supply, water depth, presence of nesting substrate, and shelter from disturbance. Submerged or emergent vegetation is needed to anchor floating nests. Successful nesting requires isolation from disturbance. The most common disturbances to these breeding colonies are water level changes, motorboats, and wind events.
Aechmophorus grebes have a conservation priority of high concern as a result of water level drawdowns for power generation, which have caused catastrophic losses to nests and decreased reproductive success.
In 2023, PAS secured funding from the Kure-Stuyvesant Trustee Council to bring new life to the Grebe Project. With this funding, PAS has been able to jumpstart an innovative pilot study to address the complex issue of how fluctuating reservoir elevation levels affect the reproductive success of nesting western and Clark's grebes.
In 2023, 2024, and 2025, PAS deployed artificial nesting platforms on Lake Almanor, built to the specifications outlined in David Riensche's 2009 publication Western and Clark’s Grebe Nest Platforms Designed for Fluctuating Water Levels. These floating platforms, if utilized, will allow for continued nesting amidst reservoir elevation drawdowns.
No platform usage was observed in 2023 or 2024, likely a result of atypically high water years, which allowed for nesting in emergent vegetation that is typically on dry land. While the abundance of emergent vegetation at the beginning of the 2023-2024 breeding seasons offered ample suitable nesting habitat, subsequent reservoir elevation drawdowns later in the seasons led to significant nest abandonment events.
In 2025, two nesting platforms were used by western grebes! This pilot study sets a precedent for effective implementation elsewhere. Due to this success, we have secured funding to extend the pilot study into 2027.
PAS will continue making improvements to encourage the Aechmophorus grebes of Lake Almanor to utilize the artificial nesting platforms.
Artificial nesting platforms on Lake Almanor
Outreach
To raise awareness, PAS conducts diverse outreach and education activities near the lakes. This includes our annual Lake Almanor Grebe Festival; sign installations around the breeding lakes to alert lake users about the grebes and their nesting areas; and the distribution of educational brochures at locations that serve each of the lakes.
We are finding ways to help conserve these significant breeding populations of Clark's and Western Grebes so that the grebes continue to migrate to our lakes for generations to come.
We are finding ways to help conserve these significant breeding populations of Clark's and Western Grebes so that the grebes continue to migrate to our lakes for generations to come.
Teaching Youth about Grebes
Since 1996, PAS has worked with youth in the region, teaching them about the grebes that nest in our area while also providing opportunities for them to forge lasting connections to the environment. We actively engage youth across Plumas, Lassen, and Sierra Counties, including Portola, Quincy, Greenville, Chester, Loyalton, Westwood, and Susanville. Teaching about grebes provides ample opportunities to reinforce important concepts such as habitat, migration, molting, foraging, adaptation, reproduction, predation, and pollution.
