Where is the noticeable, almost pure white patch prominently featured on the breeding male Bobolink?

Answer

Scapulars

The true identifying marks for the breeding male include patches of white, specifically a noticeable, almost pure white patch on the scapulars, which are the feathers covering the shoulder area.

Where is the noticeable, almost pure white patch prominently featured on the breeding male Bobolink?
animalPlumageBobolink