I've posted in favor of hawthorns. We have a thicket of them at my camp - Washington hawthorn. They have small ( 3/8" to 1/2" ) red fruit/berries. They last well into the winter. They drop the berries which hatch into seedlings. Those can be transplanted to other locations or left go to form a thicket. Grouse LOVE the berries, as do pheasants, turkeys and many other birds. The dense, thorny branches are super nesting cover for a variety of birds ( which help keep insects out of your apple, crab, plum trees! ). As for deer bedding - some of the best deer bedding cover I've ever seen here in Pa. was in hawthorn thickets. In high pressure areas in the northern AG zones of Pa., you could bet on kicking out deer AND grouse from those haw thickets. Easy to grow, not fussy, deer browse the young, tender end shoots that have no thorns. We LOVE THEM !!!
If you want a thicket you can walk thru, just space 'em out so they're not crowding each other. When they start to produce berries and you get seedlings, yank 'em, spray 'em, or transplant 'em. Ours are about 19 yrs. in the ground, and they're around 15 to 18 ft. tall and 10 to 12 ft. wide. I'm not familiar with the cockspur or the sweet-fruited ones Stu has.