羽は抜ぬけ

noun

molting; moulting

Refers to the natural process of birds shedding old feathers and growing new ones.

• 鳥とりの羽は抜ぬけの時じ期きは、餌えさを多おおめに与あたえたほうがいい。

  During the molting season, it's better to give birds extra food.