Beth MeSorley, age 13, of Fredericton, N.B., Canada, for her question:
How many feathers does a bird have?
A bird's plumage may include 1,000, 5,000 or more than 11,000 feathers of different types. During the molting season, of course, the number is greatly reduced and even the proud peacock loses his hoity toity tail feathers. The fluffy little kiwi and the smoothly groomed penguins have closely packed feathers that resemble silky hairs. Andy has never met anybody who had enough patience to count the feathers of these unusual birds.
A mallard duck in full plumage is a beauteous sight to behold. Several times a day, he smooths and waterproofs his lovely feathers. Perhaps you would like to guess. Would you say 3,126 or 5,804 or 11,903? If you suspect that a duck has more feathers than a song sparrow and fewer than a kiwi, you are on the right track.
Meantime, let's pause to survey and admire the wonders of feathery plumage in general. The birds and only the birds wear this type of clothing. It can be adjusted to keep a bird's body cool or cosily warm. Its separate feathers can be spread to catch scoops of air or smoothed to streamline through the wind. Naturally, its feathery lightness is designed to reduce excess flight baggage.
Each individual feather is a model of strength and delicacy. The central rib is a hollow shaft made of bony material, sturdy and light. The silken web that grows along each side of the shaft is a delicate structure that would put a spider to shame. It is made of barbs like fine hairs growing side by side. Along each barb there are several hundred branching barbules, each sprouting tiny hooklets. The web structure is held in shape by the interlocking barbules and the clinging hooklets. The base of the shaft is bare and there are large or small tufts of downy fluff below the neat web.
The smallish contour feathers that cover the body can be raised or lowered to hold pockets of warm air. The long, stiff pinions in the tail and wings are maneuvered to make use of the air in flight. Ducks and other water birds also wear undercoats of soft, downy feathers that have no central shafts. And somebody counted the top coat feathers of a mallard duck in full plumage. If your guess was 11,903, you are a perfect guesser.
Smaller birds have smaller feathers and smaller areas of skin to cover. The number is far from definite, but a sassy bluejay could be expected to register a protest if he had fewer than 4,000. The small, sweet singing warblers are content with 1,500 to 2,500.
These feather counts apply to birds when they are in full plumage. But feathers are exposed to a lot of wear and tear, even though their owners spend hours of daily grooming to keep them in good repair. About once each year, the old coat becomes too shabby and the molting season comes around. The worn feathers fall out a few at a time, while new ones grow in to replace them. For a couple of weeks or so, a molting bird feels like a miserable mess but his spirits perk up when he gets his shiny outfit of brand new feathers.