Your pen needs to have some sort of netting or chicken wire roof over the whole pen. The fencing needs to have 1"x 3' vermin wire on the bottom dug 18" inches into the ground. The gate needs to have a landscape timber cut to fit and trenched tightly under the gate and the gate should be tight to the posts on each side and have a treated 1x4 across the top right above the gate with very little gap between it and the gate. It may not be just red tail hawks as owls, raccoons, skunks, foxes, and members of the weasel family love to dine on chicken. I worked on a state game farm and raised pheasants for 17 years and had to deal with every kind of predator you can think of including coyotes. The vermin wire prevents animals from digging under your fence, and not just predators, wood chucks like to eat chicken food too and if they dig under you fence it provides a highway for the predators.
Your pen needs to have some sort of netting or chicken wire roof over the whole pen. The fencing needs to have 1"x 3' vermin wire on the bottom dug 18" inches into the ground. The gate needs to have a landscape timber cut to fit and trenched tightly under the gate and the gate should be tight to the posts on each side and have a treated 1x4 across the top right above the gate with very little gap between it and the gate. It may not be just red tail hawks as owls, raccoons, skunks, foxes, and members of the weasel family love to dine on chicken. I worked on a state game farm and raised pheasants for 17 years and had to deal with every kind of predator you can think of including coyotes. The vermin wire prevents animals from digging under your fence, and not just predators, wood chucks like to eat chicken food too and if they dig under you fence it provides a highway for the predators.