What causes feather loss on the lower back and head of female birds in breeding flocks?

Feather loss on the lower back and head of female birds in breeding flocks is primarily caused by males gripping feathers while mating. During the mating process, males often grasp the feathers of females for better positioning and balance. This behavior can lead to the physical pulling of feathers, especially in those areas prone to such handling.

Understanding this behavior is crucial for managing breeding flocks, as it highlights the need for monitoring pairing dynamics and possibly adjusting breeding practices to minimize stress and discomfort for the hens. While the other options can lead to issues in poultry health and welfare, they do not directly account for the specific feather loss seen in this scenario as a result of mating behaviors.