I froze enough shelled black walnuts last year to last two years so
this year I gathered them for the birds. After experimenting I found
pounding them fine enough to go though 1/4" wire mesh prevents them
from jamming in the bird feeder. I toss it all in, shells and all, and
let the birds pick through it for the crumbs. Chickadees look for tiny
insect eggs in the bark of trees so picking out walnut crumbs comes
naturally. They like anything with oil in it, so nuts and black
sunflower seeds are popular, but nuts cost too much. How many
commerical bird fees contain nuts? Here in the Great White North
(Ottawa) oil provides fuel to keep them warm.

My feeder has three compartments. Top has black walnuts and bottom
black sunflower seeds. The feeder hangs under a comercial squirrel
deflector but I've used and upside down bucket with a wire hanger
through the centre of the bottom. I removed the perches to give
chickadees better odds competing with finches who hog perches. I hang
a suet cage on the middle compartment.

Chickadees will take larger pieces of walnut in the shell but so will
squirrels which I why I crush it and put it in the feeder. Chickadees
will take walnuts and sunflower seeds from my hand. Some prefer nuts.
Others prefer seeds. The nuts last over the winter in a cool place. I
crush as needed.