HELP! Chickens perching in trees.

My chickens did the same thing last summer and I had to do a chicken hunt ever night round them up. It is my personal believe that in my case it was because the coop was too hot. I moved the coop to a shady area and added better ventilation. I haven’t had any more issues but it hasn’t gotten really hot here this summer yet.

 

I have 6 chickens that have been raised since hatching with 15 guineas. I have a chicken tractor big enough for all of them, and the guineas have recently started going up in the trees. One chick roosts in the trees with the guineas. I just leave her there. She's too high up for me to ever get her down. Sorry, I'm not much help.

 

I'm betting it's too hot in the coop.
Make sure you have adequate ventilation in coop and that there are no pests(mites, rodents, snakes) living in there.
Leave them locked in the coop/run 24/7 for a few days to a week to re-habituate them to roosting in the coop.

 

WL's could be more sensitive to heat and thus move before BA's. You could also have social issues pushing WL's out. Look into dispersing roost inside structure. Also look into increasing airflow further. When it gets really hot even my birds will shift roost site to one with more airflow. Still follow aart's procedure to get birds to shift back into structure.

 

My smallest bird is the one who starts panting first when it gets hot, she's also light colored<shrugs>.
Adding an extra roost inside might help, with both them spreading out and the one(s) who may be lower in status.
Can you post a pic of your coop?
Even if it's 'open' it still might not be setup to be conducive to airflow.
I put a fan in the east window on my copiously ventilated coop to push some cooler air inside in the late afternoon until I lock the coop after dark.
It really helps cool off the interior.