Perhaps they mistook the darkness of this chilly, lowering sky for the onset of night, or perhaps they sensed the arrival of a storm, and so returned early to the warmth of their wooden pigeonry.

也许是误认为这灰暗的凄冷的天空为夜色的来袭，或是也预感到风雨的将至，遂过早地飞回它们温暖的木舍。