We have Downy Woodpecker pairs coming to the feeders and nesting nearby. There is one particular male who comes often and all of the white feathers on his body are stained a deep yellow. I think this is from pollen. I wondered if it could be from sap but the feathers don’t look sticky. I cannot think of what else it could be but pollen.
The same thing occurred last year with a pair of these woodpeckers. Later on in the season, none of the Downy’s had the yellow feathers so I assumed the staining eventually washed off via bathing and rain and/or perhaps the late summer molt replaced the stained feathers. I don’t think I have ever seen this before last year and I have seen many a Downy in my lifetime.