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Unformatted text preview: fluffy. They trap an insulating layer of air close to the body and so reduce heat losses. The barbs and barbules of the flight and covert (or contour) feathers are organised in a regular way forming a smooth, water resistant cover. The barbules overlap so that the hooks on one set of barbules engage with grooves on the other set rather like Velcro. If the feathers get damaged in flight, they can be restored to shape by preening. barbs and barbules shaft shaft barbs and barbules hook in lower barbule locks into trough in upper barbule barb (c) Simplified model of interlocking mechanism of barbules (a) Down feathers ( b) Flight feather Feather structure D.G. Mackean vane...
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This note was uploaded on 11/29/2011 for the course BIO 218 taught by Professor Young during the Fall '11 term at BYU.
- Fall '11