Indigestible

Looks like feathers.
Some bone fragments.
These are pellets hawked up by various birds. The above three photos were all taken in rather close proximity, but under different trees. Examples in the third picture were found all bunched up like this. Too small for Great Horned, too big for Saw-Whet.
Owl pellets are the most famous, but diurnal raptors and others others spit them up, too. Here are some I suspect are from a Belted Kingfisher.
This one has seed husks in it.
I wonder if these are Saw-whet. There were a few more besides these under this tree.
Same batch, but with a flash.