This Yellow-bellied Sapsucker has been seen in southeast Portland for the past week. It is a young male, molting into his first adult plumage. The timing of this bird’s molt is key to distinguishing him from the very similar Red-naped Sapsucker. Young Red-napes achieve an adult-like head pattern by early October, while young Yellow-bellies gradually attain this pattern over the winter.
Yellow-bellied Sapsuckers normally winter across the the southeastern U.S. and into Central America. They breed across Canada and the northeastern U.S. Red-naped Sapsuckers are common breeders in eastern Oregon, only occasionally occurring west of the Cascade Crest, and winter in the southwestern U.S. and Mexico.
Ethical Birder 
Funny but I regularly have seen them year around in a Eucalyiptus tree in my front yard for about the last 14 years and didn’t think that they were all that uncommon. They must nest here also since I see them also in the spring and summer months. They do damage the tree but a lot of smaller birds also use the sap and insects that it attracts as a food source in the wiinter months including hummingbirds. I live outside of Myrtle Point about 30 miles from Coos Bay.
Keith, Yellow-bellied Sapsuckers are quite rare in Oregon, with one or two reported each winter in recent years. Red-breasted Sapsuckers are year-round residents in your area, so that would be more likely, but stranger things have happened.