While birding on the Lafayette Reservoir trail on the south woodsy side on Wednesday, we saw a foraging flock of 10-12 “Myrtle” type yellow-rumped warblers. Most appeared very pale (black/white/gray) without yellow cast, except on the rump. Some had a slight tinge of yellow on the throat or flank. One male had a yellow throat. Someone mentioned that YRWA in Washington State are Myrtle group. It made me wonder whether there is more of cline between the two types. Any comments?
