The chicks will be going in a brooder for about 4 weeks until I move them to the coop. I don't want the perches to be too tall because the walls of the brooder are about 3-3 1/2 feet. Will the chicks be able to jump out if there's perches?They'll be flying high soon if they aren't already, so you don't need to worry that much about height. You can always make two roosts at different heights - one lower (about a foot off the ground), the other one higher. That way they can get to the higher one easier by using the lower one as an intermediate step, and when they get too big for the short roost, they can just use the tall one. They like heights even when they are young, and if they have a way to get to it, they'd gladly roost by the ceiling too
I have 3 permanent roosts in my coop, all made from thick tree branches (3" diameter). One is about a foot off the ground, one is 4 feet off the ground, and one is between the two. They are spaced about 1 foot from each other horizontally, so whoever is on the top roost doesn't poop on the ones below. I hatch chicks every year (in the coop, with a broody) so I did this to allow all ages to roost somewhere. And guess what - nobody ever uses the roost that's 1 foot off the ground! The grownups sleep on the top roost, and the chicks use the other two roosts to hop up to the top roost and sleep there with their mom. They start doing this at under 2 weeks old. So, if your chicks are going to be going straight to the coop, I'd say don't waste your time with baby roosts. Make big roosts that they'll use when grown, and just provide some stepping roost (or ramp) for them to get there. If they're going in a brooder, then you can make whatever size roost will fit in the brooder.
Not really. Anything that would be safe as bedding would be safe as a perch too.
Without a top on the brooder? Yes, they could. Chicks are better jumpers than many adults because they're so light.
I agree, not really. If you use sawn wood I'd sandpaper it down a little to remove splinters.
I've had 2-week-old chicks fly up 2' and out 3' when Mama took them to the roost. Not just jumping, flying. There is a reason their flight feathers come in so early.
Wow, 4 weeks in a brooder, for 3-week-olds? Why so long? Yes they will jump/fly out if the brooder doesn't have a top, even without perches, and with perches it's pretty much guaranteed. They'll need to be outside and will try their best to get out - fly out, break out, eat their way out. Last year was the longest I kept chicks in a brooder - 5 weeks - and they ate through the cardboard box they were in, trying to get out! It was a chest freezer box, for 5 chicks, so it wasn't small, but they looked comically inadequate in there - big, rowdy, loud, smelly and desperate to get out. 7 weeks is just too much. If you don't have any seriously compelling reason to keep them in a brooder that long, don't.
