|Nesting cormorants--upper left Double-crested; lower right Brandt's.|
Photographed at Newport, Oregon on July 21, 2012 by Greg Gillson
Take a close look at the cormorant's nests. Do you note that they are constructed differently?
According to The Audubon Encyclopedia of North American Birds, the Brandt's Cormorant (lower right in front) builds a nest of marine plants, mosses, and grasses in a circular nest. On the right hand side of the upper piling are two fuzzy brown Brandt's Cormorant chicks.
On the left side of the upper piling is a nest of Double-crested Cormorant. Notice that is is built of "sticks and weed stems, lined with leafy twigs and grass."
There is actually a third species, Pelagic Cormorant in this photo. See the dark form up on the bridge just above the upper right hand Brandt's Cormorant? That's where they build their nests. On natural substrates they build nests on "remote and precipitous cliffs" of seaweed, grass, and rubbish.