Ornicopia 9: Feathers (An Extremely Strong, Light Plane of Great Flexibility)

A.

319.  How many individual parts does a featherhave?  
The parts of a single featheradd up to more than a million individual units, many of them so small they canonly be seen with the help of a microscope. These parts interlock to form an extremely strong, light plane of greatflexibility.

B.

C.
 

321.  Are the feathers of a bird alive? 
As long as the feather is growing, its softcentral is fed with blood vessels which supply pigments and food.  Once the feather is fully mature, that is,has lost all of its sheath and is fully expanded, it hardens, the food supplyis cut off, and the whole structure is made up of dead epidermis.  The feather may then be considered dead,though it continues to be firmly clasped by the feather follilcle until thenext

molt.

 

D.

E.

 

326.  What are down feathers? 
Theseare soft feathers without a shaft and having barbs that are but soft fluffytufts.  They are extremely strong andresilient.  They provide the covering ofmany newly-hatched birds , particularly those of the precocial group.  Some species of birds as adults have a downundercoating beneath their contour feathers. Ducks and geese have such an undercoating.

F.

G.

327.  What are powder-down feathers? 

Thesescarcely seem like feathers at all.  Theyform a powdery substance on some areas of the skin of such birds as herons andbitterns.  These birds rub their bills inthe powder-down feathers and spread the resulting powder over their plumage,giving it a “bloom” which rubs off when the bird is handled.

H.

I. 

Key to Illustrations:

A.  Indian peacock photographed by Jebulon.

B.  Feather structure diagram.

C. Parts of the feather: (1) Vane; (2) Rachis; (3) Barb; (4) After-Feather; (5) Hollow shaft (calamus)

D.  Feather structure of a blue-and-yellow Macaw.

E.  Common female eider duck with down photographed by Frederic Levier.

F.  Plumes. Illustré par AdolpheMillot dans Larousse pour tous [1907-1910]. Aigle, Hibou, Goura,Argus, Paon, Autruche, Canard, Dindon, Pintade, Aigrette, Faisan etc.

G.  Mealy parrot showing powder down, photographed in Florida by Don Kasak.

H.  Archaeopteryx  sometimesreferred to by its German name Urvogel ("originalbird" or "first bird"), is a genus of theropod dinosaur.  Late Jurassic Period (150 million years ago). 

I.  Shaft of male Indian Peafowl tail feather (Pavocristatus); Feather microstructure showing interlockingbarbules. Photographed by Michael Maggs.

From:  1001 Questions Answered About Birds by Allan D. Cruickshank and Helen G. Cruickshank (Toronto, General Publishing Company, 1958)

Ornicopia 3 -- Feathers

 

307.  In what way are birds unlike any other member of the animal kingdom?  Of all forms of animal life on this earth, birds and only birds have feathers.  All birds possess them.

311.  From an engineering standpoint, what are the chief characteristics of a feather?  A feather is the most complex growth of skin known to be formed by any animal.  It is one of the lightest and at the same time one of the strongest materials formed by any creature.   It is durable, complex and flexible, a superb functional structure for both flight and heat retention.

 

312.  How many feathers does a bird have?  The number of feathers a bird has usually increases with its size.  Summer counts on a hummingbird indicate that it has about 1,500 feathers at that period.  A robin has almost 3,000 feathers while a whistling swan has more than 25,000.

Illustrations (upper to lower):

Albrecht Durer, Wing of a Blue Roller, 1512, Gouache and watercolor on vellum, Graphische Sammlung Albertina

New Guinea Parrot

Upper and lower surfaces of a rock dove's wing, diagrams from Pettingill, Jr. 1985

Hummingbird

American Robin

Whistling Swan

Text from:  1001 Questions Answered About Birds by Allan D. Cruickshank and Helen G. Cruickshank (Toronto, General Publishing Company, 1958)