John Avise continues his series on “faux ducks”—those birds that many people think are ducks but aren’t. Your job is to guess the species after looking at the photos. You can check your answer afterwards by going below the fold, where you can find the ID, some of John’s Fun Faux Duck Fax, and a range map. John’s captions are indented; click photos to enlarge them.
Adult frontal view:
Another adult side view:
Dorsal view:
Twisting neck:
Sleeping:
Non-breeding adult:
Oil-soiled bird showing reflection:
Clark’s (right) and Western (left) Grebes:
Showing aggression against Western Grebe:
Adult (with fish) and juvenile
Click “read more” for ID, Faux Duck Fax, and a range map:
ID: Clark’s Grebe (Aechmophorus clarkii)
In terms of appearance, behavior, and lifestyle, this species very closely resembles last week’s bird, the Western Grebe (Aechmophorus occidentalis). Indeed, until the 1980’s these two forms were considered conspecific morphs, but then it was discovered that positive assortative mating (mating of like with like) generally characterizes birds in this taxonomic complex. Also present are some very subtle morphological differences: Clark’s Grebe has a slightly brighter yellow bill, slightly grayer back, and when in full breeding condition its eyes are mostly surrounded by white feathers, while those of the Western Grebe are surrounded by black. But there also seems to be geographic as well as seasonal variation in these features, which complicates matters considerably. And to further complicate taxonomic assignments, birds intermediate in appearance sometimes are observed, and it is not necessarily clear whether these reflect normal variation within one or the other species, or perhaps are interspecific hybrids. Although most of the modern field-guides present the Western and Clark’s Grebe as two separate species, I usually don’t agonize too much about trying to tell them apart, especially when I see them poorly or at a distance.
Range map from the Cornell site:
Yep – Grebe – got it!
We need a Faux Grebe post now!
ha ha. A faux grebe is just a duck.
Yes, but we’ll soon start highlighting another group of birds that qualify as faux grebes perhaps even more so than faux ducks!
I look forward to that!
Lake Lowell (Deer Flat National Wildlife Refuge) has thousands of Western and Clark’s grebes. Of the two, the Western are much more numerous. Very hard to tell the difference from a distance.
Is the coloring of that juvenile unusual?
No, juvenile Clark’s Grebes are all nearly white, and slightly lighter in color than those of Western Grebes.
Umm, thanks.
I guessed Grebe…I think because of the red eyes. I didn’t know it was Clark’s though, so only half right.