This never works for long.
First, you wrote that your birds were 5 weeks old so they are still chicks and with no adult chickens to teach them about roosting in the coop, they won't do it on their own at that age. They are of an age where they are more likely to huddle up in a pile in the corner somewhere. But with your run being completely vulnerable to predators due to the use of chicken wire instead of 1/2" hardware cloth, this is very bad for them.
Eventually they will use the coop. Can you post pictures of the interior and of all the ventilation you have other than that window?
I would recommend flipping the closure on the window over to have it top hinged so it can be propped or hung open during rain and it will keep water from entering the coop. A glass or lexan window would be better to let light in when it is closed.
One other potential issue is the placement of the coop out in the open like that. Birds feel much more secure near structure: trees, shrubs, buildings so they can run to shelter if they are attacked. And there are tremendous benefits to having lots of shade on the coop and run. If you can relocate the setup to a shadier spot, I would do that.
When you are ready to let them out, start by releasing them about 2 hours before roost time (after they've learned to roost). This way, they will not want to wander far from the coop. Once they routinely go back to roost, you can
This never works for long.
First, you wrote that your birds were 5 weeks old so they are still chicks and with no adult chickens to teach them about roosting in the coop, they won't do it on their own at that age. They are of an age where they are more likely to huddle up in a pile in the corner somewhere. But with your run being completely vulnerable to predators due to the use of chicken wire instead of 1/2" hardware cloth, this is very bad for them.
Eventually they will use the coop. Can you post pictures of the interior and of all the ventilation you have other than that window?
I would recommend flipping the closure on the window over to have it top hinged so it can be propped or hung open during rain and it will keep water from entering the coop. A glass or lexan window would be better to let light in when it is closed.
One other potential issue is the placement of the coop out in the open like that. Birds feel much more secure near structure: trees, shrubs, buildings so they can run to shelter if they are attacked. And there are tremendous benefits to having lots of shade on the coop and run. If you can relocate the setup to a shadier spot, I would do that.
When you are ready to let them out, start by releasing them about 2 hours before roost time (after they've learned to roost). This way, they will not want to wander far from the coop. Once they routinely go back to roost, you can start releasing them earlier and earlier.
start releasing them earlier and earlier.