Just transported 9 hives from the mountains in NC back home. Total travel time was about 2 hours and this was done after dark.
My hives all have screened bottom boards and screen mesh was used to close the entrances. I waited until 6:30 the next morning to unload them.
2 hives experienced a total meltdown and all bees were lost. The 2 that were lost had migratory covers which allowed for no top ventilation. 6 of the others had telespoping covers and 1 was also migratory.
Did the bees more likely die in transit or sitting on the trailer until morning? What can be done to prevent this in the future? (please be more specific than "give them more air")