They are hastening back to their warm wooden dovecote earlier than usual perhaps because they have mistaken the bleak leaden sky for nightfall or because of their presentiment of a storm.

• 也许是误认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。