It could not have been more opportune for me to have these two warblers sighted one after another in the same location, practically the same tree. It's also a first for me to sight the Arctic Warbler and the Eastern Crowned Warbler foraging close to each other.
I couldn't have asked for a more ideal juxtaposition either to enable both diagnostic features.
Dark tip at lower mandible vs ...
... Clean lower mandible
And this pose really is perfect - all the features displayed in full - median coronal stripe, dark upper mandible and clear lower mandible sans dark tip, yellow vent.
