Bird's nest

Him Indoors has noted that there is a floral theme to my blipfoto entries. I like photographing flowers; they don't move, or get scared away by over exuberance.

A bitty day today, doing a bit of this and a bit of that. Out on my wanders I noticed a small bird's nest lying on the ground. Did it fall out of a tree, or did it come out of the hole under the grass (see extras)? There were a few piles of moss around said hole. What bird made this nest? An LBJ for sure, but which one?