Microscopy Primer
Light and Color
Microscope Basics
Special Techniques
Digital Imaging
Confocal Microscopy
Live-Cell Imaging
Microscopy Museum
Virtual Microscopy
Web Resources
License Info
Image Use
Custom Photos
Site Info
Contact Us

The Galleries:

Photo Gallery
Silicon Zoo
Chip Shots
DNA Gallery
Amino Acids
Religion Collection
Cocktail Collection
Screen Savers
Win Wallpaper
Mac Wallpaper
Movie Gallery

Differential Interference Contrast Image Gallery

Down Feathers

Feathers keep birds warm, help them fly, and aid in mate identification, but are also useful to humans who have been utilizing them for thousands of years. Flexible, lightweight, strong, and beautiful, the specialized epidermal growths have been utilized for diverse purposes, such as fashionable adornments, writing utensils, religious symbols, and stuffing for bedding.

All feathers are primarily composed of the fibrous protein keratin, but the size and number of feathers a bird possesses is dependent upon species. The bird with the least number of feathers is the ruby hummingbird Archilochus colubris, which features a total of 940 when in full plumage. Contrariwise, the whistling swan Cygnus columbianus may have as many as 25,000 feathers in the wintertime. The amount of feathers a bird exhibits varies by season because they are periodically molted and replaced by new growth.

There are three basic types of feathers, each with its own set of specific functions. Contour feathers line the wings, tails, and backs of birds, giving them a defined shape and acting as aerodynamic structures. Beneath them, lie the soft, fluffy feathers commonly referred to as down. As anyone who has ever used a down comforter or sleeping bag should know, down feathers are excellent insulators. Thus, their primary function is to maintain the proper body temperature of birds, a task that they are aided in by hair feathers. Sometimes alternatively known as filoplumes, hair feathers are also believed to function as pressure and vibration receptors that sense the location of other feathers so that they can be appropriately adjusted.


Questions or comments? Send us an email.
© 1998-2022 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last modification: Friday, Nov 13, 2015 at 02:19 PM
Access Count Since April 22, 2003: 23598
For more information on microscope manufacturers,
use the buttons below to navigate to their websites: