Eight T-posts...depending on how tall you are, at least 6 1/2 feet tall t-posts because they go into the ground about 12-18". Chicken wire - no larger than 1 inch holes. Sink the posts. Wrap the chicken wire - have the wire extend on the ground about a foot around the pen - you'll have to cut a slit at the corners. Secure the wire to T-posts with zip ties. Use some more chicken wire or plastic deer/bird netting and cover the top. You will need to figure out how you want to do a gate. I have seen gates made of wood and tied with rope to the t-posts and I have seen just a chicken wire flap with the opening edge stapled to a piece of 1x2. The flap has to be a couple feet longer than the door opening so that you can secure it well without leaving any seam openings.
Around the outside where you have chicken wire on the ground, dump dirt, pile some rocks or like we did, we used cut logs. This will keep something from digging under walls of your pen because a predator would have to know to start digging a foot away from the side of your pen and then dig a foot long tunnel to get to the birds..they won't do that.
You can put plastic or a tarp over one end of your pen. Make a few roosts with cinderblocks and landscaping timbers or 4x4's (put the wood in the cinder block holes and you can make the blocks as high as you'd like. Put the roosts at least partly under the tarp so the birds can roost there in the rain or in the shade of the tarp if it's hot. Feeder in the area under the tarp..somewhat centered so that if it is windy rain, you won't get real soggy food in the feeder. Waterer can go by the door...so you don't have to haul heavy water thru the pen.
When you are done with the pen...move the logs, cut the zip ties, roll up your chicken wire to be used again. You will have to rock the t-posts back and forth to loosen them as you pull up...hard work, but they will come up unless you set one into a root..LOL.
