Winter is the time to study gulls in the Willamette Valley. If you feel a little overwhelmed by some of the fine plumage details described in birding references, consider looking at the shape of the bird. The silhouette above can be identified to species with reasonable certainty. The three things to consider are 1. the shape of the bill (small and slender, but with a noticeable gonydeal bulge), 2. the shape of the head (fairly large with a sloping forehead), and 3. how far the wings extend beyond the tail.
I’m teaching a class on Willamette Valley gulls for Portland Audubon on January 18, 2012, with a local field trip on January 21. We will discuss plumage details, but also the shape of each species. Shape is much more useful when trying to ID distant birds, birds in bad light, or birds in my typically grainy photos. For information on the class, or to register, click here.