Star-spangled back

  

Red-throated Loon (Gavia stellata), Scituate Harbor, MA, on 9 December 2025.

Here's the entire bird (below). Note the spangled patterning on the back.  The species name — "stellata" — apparently means "set with stars" and refers to this beautiful design in the loon's non-breeding plumage.  [You can click on the images for larger versions.]