Today was in the high 70's, low 80's. The pen has a steel roof, so they should have had plenty of shade, the area they were in has lots of late day shade, I would be surprised if they died to heat.
There was an obvious place where something got under the pen to eat the 1 bird, however no other...
Today my wife and I came home to 8 dead meat birds in our 4x8 chicken tractor, they were approximately 2 months old.
We fed them less than 24 hrs ago, their waterer was still full.
1 had been mutilated however the other 7 were un touched, I believe the mutilated one may have possibly been...