Like the Bay-breasted, the Chestnut-sided's name refers to horse colour terminology. I'm glad there isn't a roan warbler or a grey warbler, but can mostly handle these two. And when they were named it wouldn't have been the least bit obscure, and at least the bird really is chestnut-sided.
Hundred percent crop, and the bokeh-ghosts of various other sticks give some indication why I'm pleased it's in focus at all. Also from Trinity Bellwoods Park.