size of hole for chukar to eat

[chickendad]

New to chukar, have had coturix quail for years. what size hole do i need in my cage for chukar to reach their head through and eat.
they have 1 inch holes/wire openings in wire to reach through to get food out of trough. i have never seen them eat- they act like i torture them by the reaction of me going near the cage.(these are some CRAZY birds!) i know feed is missing/being eaten but they are 4 weeks old and getting bigger