The Meaning of Birds by Simon Barnes

This book is beautifully put together, with lots of gorgeous line drawings of birds gracing it's pages, and the chapters are outlined with an eye towards the non-scientist. If you are a backyard birder (as I aspire to be) there are a lot of charming and interesting facts. I have been preparing for a birding trip to the Galapagos, and have spent the last several months beefing up my birding knowledge, so as a result it gets harder and harder to learn something completely new. My pearl from this is that there are three things that are responsible for the color of feathers: Porphyrins, carotenoids, and melanin. Porphyrins are produced by modifying amino acids. Although the exact chemical structure of each porphyrin differs, they all share a common trait. They fluoresce a bright red when exposed to ultraviolet light, much the way certain rocks and minerals are known to do. Porphyrins produce a range of colors, including pink, browns, reds, and greens. Porphyrins are found in some owls, pigeons and gallinaceous species. They can also produce the brilliant greens and reds of turacos. Carotenoids are produced by plants, and are acquired by eating plants or by eating something that has eaten a plant. Carotenoids are responsible for the bright yellows seen in goldfinches and Yellow Warblers as well as the brilliant orangish yellow of the male Blackburnian Warbler. Most important for me in the short run is that they are responsible for the blue feet on the Blue Footed Booby, and that the bluer the male's feet are, the more attractive a mate he appears to be. The final pigmenting agent is melanin. Melanin occurs as tiny granules of color in both the skin and feathers of birds. Depending on their concentration and location, melanin can produce colors ranging from the darkest black to reddish browns and pale yellows. Melanin provides more than just coloration. Feathers that contain melanin are stronger and more resistant to wear than feathers without melanin. Feathers without any pigmentation are the weakest of all. Many otherwise all white birds have black feathers on their wings or black wingtips. These flight feathers are the ones most subject to wear and tear. The melanin causing the tips to appear black also provides extra strength.