How? Under their nearly impenetrable coat of contour feathers lies a dense layer of soft, fluffy feathers called down, which may be up to two thirds of an inch [1.7 cm] thick and cover most of the duck’s body.
अनेक पक्ष्यांच्या आवरण पिच्छांत अधून मधून बारीकशी लांब पिसे असतात ज्यांना रोम पिच्छे तसेच भुकटी पिच्छे म्हणतात.