Powder down
Powder downs are special feathers in certain species of birds , such as parrots or herons , in which the tip of the regrowing feather constantly breaks down into fine dust. This dust makes the plumage water-repellent, and the birds use it for cleaning, since in these birds the rump gland is often severely reduced.
literature
- Ernst Schüz : Contribution to the knowledge of powder formation in birds , J. f. Ornithology, Volume 75, 1927, pp. 86-223
- Hans Schildmacher: Introduction to Ornithology , Stuttgart, New York 1982, ISBN 3-437-20266-9 , p. 30