Aechmophorus occidentalis
(Western Grebe)

Physical Description:
Size:22-29" (56-74 cm). This is a large black and white grebe. It's long neck is white on the front and black on the back. It's black cap extends down below the eye. Body black. Bill yellow. Sexes similar.

Similar Species- The Clark's Grebe and Western Grebe were formerly considered to be the same species. The distinguishing morphological difference between them is that the cap on the Clark's Grebe does not extend past the eye. The Clark's Grebe's bill is also orange-yellow.

Song:
A two-part crick-crick. Heard most often during breeding season, but also heard occasionally during winter.

Distribution:
Breeds mainly from western Canada, east to southwestern Manitoba, and south through U.S. from California and Utah east to upper midwestern states. Winters mainly along Pacific Coast from southeastern Alaska to northwestern Mexico.

Found on marshes, lakes, and bays. During migration and in winter, also found on sheltered seacoasts, less frequently along rivers. In Idaho, prefers large rivers and reservoirs that include shallow water areas with emergent vegetation.

Diet:
Diet consists mainly of fishes; opportunistic as to species eaten. Also eats insects (adults and larvae, especially in spring and summer), mollusks, crabs, marine worms, and salamanders. Ingests feathers and small stones.

Ecology:
Builds platform nest on shallow water. Nests in colonies of sometimes hundreds or thousands of birds. In Idaho, nests in large colonies and isolated pairs that are susceptible to water fluctuations. Young may ride on backs of adults. Individuals dive from water surface to obtain food.

Reported average clutch size is about 2.2-3.3 in southeastern Idaho, 2.5 in Utah, 3.4 in Colorado, and 4.2 in North Dakota. Dump nesting may result in large clutch in one nest. Both adults incubate, in turn. Incubation lasts 3-4 wk. Brood size is usually 1-3. Young are tended by both parents

Conservation:

Element Code:	ABNCA04010
Status:	Protected nongame species
Global Rank:	G5
State Rank:	S4
National Rank:	N5B,N5N

Important State References:
Trost, C.H. 1994. The status and distribution of colonial waterbirds in northern Idaho and selected species in southern Idaho, 1994. Dept. Biol. Sciences, Idaho St. Univ., Pocatello. 31pp.