Cornish Bird Wings Drooping

[AGRowles]

I have a batch of 5 week old Cornish, no losses yet and seeing if I can keep it that way! They are all running around, foraging in their chicken tractor and quite active. One of them however I notice when I feed them, he goes from sitting to standing back to sitting while he is eating (the others remain standing while they feed). I also notice his wings droop badly when he is standing. Anyone know what could be causing this?

 

[HappyClucker7]

Is it hot where you are? Maybe he is especially sensitive to heat like one of my barred rocks.

 

[AGRowles]

Is it hot where you are? Maybe he is especially sensitive to heat like one of my barred rocks.

Not particularly hot. There's mild panting but today is very cool and I noticed it again this morning.

 

[AGRowles]

So I jinxed myself.. Found a dead hen this AM (the bird in my last question was a male). So last night was abnormally cold and rainy in New York. Down to low 40's I would guess + rain. They are in a chicken Tractor 24/7 with a tarp over it so maybe with wind chill one of the smaller ones could have succumbed? Any thoughts?