In April our smaller Podiceps grebes, Horned and Eared, molt dramatically into alternate plumage. In winter it can sometimes be a challenge to distinguish the Horned Grebe (Podiceps auritus), from the Eared Grebe (Podiceps nigricollis), but no difficulty now. On April 19th our birding group of Vagrants spent time at Bodega Bay. The highlight for me was this cooperative Horned Grebe swimming in the channel by the sportfishing boats at Porto Bodega, accessed from Bay Front Road. We watched it from the dock just aft of the New Sea Angler.
The white tip on the bill is actually a very good field mark for the Horned Grebe, as the white tip is not seen on the Eared Grebe. The light orange feathers on the side of the head form a solid swath (wispy in Eared), and the black of the cheek transitions sharply to a rufous neck.
A second photo give us a better look at the red pupil. Many grebes have red pupils, but in Horned Grebe the inner margin of the iris next to the pupil has a white margin, something I had not noticed before. Best seen in a cropped view here. The white margin is not present on the Eared Grebe. Better use a scope if looking for this field mark!
One last shot of the same Horned Grebe, showing rufous on the flank and some gray in the back. Note how the Horned Grebe can also have a "high-riding" rear end, as seen in the Eared. The unfeathered fleshy bare tract from eye to bill is seen in a number of grebe species.
To end on a confusing ironic note, the scientific name for Horned, Podiceps auritus, translates to "Eared Grebe"! And of course the Eared Grebe, Podiceps nigricollis means "Black-necked Grebe", which is the name used in Europe for Eared Grebe.
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