Re: the "infamous" Indigo Bunting, and a boring Pacific Loon
First off, welcome back. Secondly, thanks so much for bringing up the putative INBU again, as calm is highly overrated. I like your idea of an ice-cream scooper being the culprit, especially as vanilla was clearly involved. I haven't seen Nancy's photos, but one of Eric Kallen's does show a discrete slash of downy gray feathers across the lower belly, indicative of some missing feathers. Apart from that, I don't think your theory explains the bulk of the vanilla feathers. Plus, the presence of blue-centered undertail coverts with white fringes is odd in and of itself. (BTW, any opinion you'd like to share about Trump, while you're at it?).
Source: SanDiegoRegionBirding Latest Reports