Answer 3
Photo #3, February 17, 2008
One bird here is obviously a gull, and reading the previous quiz might have given you a clue to its identity- a bulky gull with a dark gray mantle, large and bright yellow bill that looks thicker toward the tip, and a rather dome-shaped head that lacks any apparent gray streaking or smudging—yes, it's another adult Western Gull. The other birds are all obviously large (using the Western Gull for size comparison), entirely black or blackish birds with short legs, a long neck, and a fairly long straight bill with a hook at the tip—all this pretty easily adds up to a flock of resting cormorants. We have three species in the county, though, all of them common, and all regularly rest on coastal rocks in winter. So what kind are these?
Looking over this group, a few of these look somewhat smaller than the rest, and more slender overall (at the lower right, lower center, lower left, plus one between larger cormorants third from the left). These birds share certain other distinctive structural features, including a very thin neck that looks proportionately long, a small head just barely wider than the neck, and a thin bill. Though color is not easy to judge in this photo, they also seem somehow deeper black than the larger cormorants, and a bit glossier. These are all distinguishing features of Pelagic Cormorants. Though these are sitting with other cormorants atop the rock in this case, Pelagics often rest on narrow ledges on the sides of steep cliffs, locations not usually favored by the other two. The thin-necked look is quite obvious in flight, and they usually hold their neck relatively straight.
The other cormorants here look bigger, bulkier, thicker-necked and larger-headed, but they are not all the same. Most of the birds clustered on the left have a very upright stance, and appear relatively short-tailed. While the head looks big, it forms a smooth curve with the back of the neck. The plumage (to the extent we can tell from this distant picture) looks fairly flat black. These are Brandt's Cormorants, the most numerous of our three local species. Closer, or in better light, a paler (buff-brown) band of feathering is visible behind the bare skin of the throat pouch, another good field mark. In flight, these hold their necks fairly straight, but slightly raised (not as straight or stick-like as Pelagics).
Then there are four birds in line with the Western Gull (two to the right and two to the left) that look different from the others. They are large, heavy, big-headed birds like the Brandt's, but seem longer-tailed, flatter-headed, and are standing less upright than either the Brandt's or the Pelagics. They also look a bit browner than the others, especially on the back and wings. The face and throat are visible on three of them, and show bright orange, the most obvious clue that these are Double-crested Cormorants, but the structural details can distinguish them when the throat color cannot be seen. In flight, these hold their necks with a distinct upward kink, giving them a distinctive shape. They tend to fly higher than the other two (Brandt's and Pelagics usually fly close to the surface of the water). Double-crests are also the only local cormorant likely to be see flying over land or perching in trees, and are the only species regular in most fresh-water environments (Pelagics will go up some coastal streams a ways, but otherwise stay on the ocean, and Brandt's are very rare away from the sea.)
Below is the quiz photo with the cormorants labeled (B=Brandt's, D=Double-crested, P=Pelagic.)
These cormorants were on the outer rock off West Cliff Drive at Columbia Street on February 17, 2008.
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