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GAP Analysis Predicted Distribution Map

Western Grebe (Aechmoporus occidentalis)

Species Code: AEOC

This is an "at risk" species

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Breeding Range Map
The green area shows the predicted habitats for breeding only.
© NatureMapping Program

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Predicted breeding range

= Core Habitat
= Marginal Habitat


Western grebe photo

Fact Sheet: Basic (Grades K-6) | Advanced

Breeding Range Map
The green area shows the predicted habitats for breeding only. The habitats were identified using 1991 satellite imagery, Breeding Bird Atlas (BBA), other datasets and experts throughout the state, as part of the Washington Gap Analysis Project. Habitats used during non-breeding months and migratory rest-stops were not mapped.

NatureMapping observations map   Map with Breeding 
Bird Atlas records
Observations | Historic Gap points

Metadata (Data about data or how the map was made)


This species is locally common on large ponds and reservoirs in arid areas of eastern Washington, especially Moses Lake and Potholes Reservoir in Grant County. This grebe is also known from ponds along Crab Creek and Frenchman Hills Waterway, in many ponds in the Columbia National Wildlife Refuge, and other locations including Lake Lenore and Banks Lake.

Good habitats in core areas of use were freshwater/wetlands in the Central Arid Steppe and Big Sage/Fescue zones.

Outside of the mapped distribution, Western Grebes may be found as non-breeding summer residents or migrants. During the nesting season this species is highly colonial. Colonies are formed as a few pairs nest among developing vegetation, followed by more pairs nesting as "satellites", and so on until there are many pairs nesting in a fairly large colony. The nest is a floating vegetation mat anchored to developing vegetation. The 'possible' BBA records along the Columbia between Kittitas and Grant Counties are most likely of non-breeding individuals, since the river is deep, flanked by steep cliffs, and has little suitable emergent vegetation in the area.

Translated from the Washington Gap Analysis Bird Volume by Uchenna Bright
Text edited by Gussie Litwer
Webpage designed by Dave Lester