Location and number of CBC count circles and <i>Aechmophorus</i> spp. abundance in eight wintering regions.

Coastal and interior circles are those <50 km or ≥50 km from the coast, respectively (see Methods). Mean count per circle is averaged across all 36 years and does not account for trend. Proportion WEGR refers to the percentage of all observations to species that were identified as western grebes (Aechmophorus occidentalis) since the split of western and Clark’s grebes in 1985. 1The Salish Sea includes the inland network of waterways in southern British Columbia and northern Washington and includes the Strait of Georgia, Strait of Juan de Fuca, and Puget Sound.