50 Bird - Lore 



black bird, as the case might be, that so faint a display of color or of markings 

 could produce so brilliant an effect, combined with similar feathers in suffi- 

 cient quantity. 



By observing carefully, anyone can detect another fact about feathers, 

 namely, that they are not all colored in the same way. Some feathers show 

 the same color in any light, others change from one shade to another. Some 

 colors are dull and some are metallic and glistening. Some show rainbow hues 

 and others only one. It is a good test of one's powers of observation to give 

 examples of these different colorings, just as it is of advantage to be able to 

 give examples of the different markings on different birds. 



An especially good winter exercise is a review of the common birds by 

 families, in the order arranged by the American Ornithologists' Union, with 

 this one point of the color and markings of plumage in mind. 



Coming back to the matter of the different ways in which feathers are col- 

 ored or may appear to be colored, we find ourselves confronted by a somewhat 

 complicated subject. It is of little use, however, to pass over a point or to 

 give up trying to understand it because it seems difficult, and so let us at least 

 learn the fact that there are different ways of producing color-effects in the 

 plumage of birds, as well as elsewhere. 



The three most general color-effects are: 



1. Those due to coloring-matter (pigment) in the feather itself. 



Black, red, yellow, brown and some shades of green are examples of these color- 

 effects. Brown is a combination of red and black coloring-matter. In pigeons, yellow 

 has been found to be red in dilute quantity. White is not a color, but the result of a 

 lack of coloring-matter. 



The colors in this list always show the same in any light. 



2. Those due to the effect of light on the surface of feathers which con- 

 tain coloring- matter, with especial references to the way in which the color- 

 ing-matter is distributed. 



In this list belong all shades of blue, nearly all shades of green, and a few shades of 

 yellow. It is a curious fact that, although there are birds blue as the sky and others 

 blue as indigo, no blue coloring-matter has been found in their feathers. Either brown or 

 black is the basis of blue color. Feathers with smooth surfaces give a glossy color-effect. 



3. Those due to light-effects on the surface of feathers with less reference to 

 coloring-matter than to the form and arrangement of the different parts of 

 the feather. 



We learned in the last exercise, that a feather is made up of many parts, 

 and that its smooth, even vane can be pulled apart into tiny barbs, barbules, 

 and barbicels. Not all feathers, however, have barbicels, and not all have the 

 barbules arranged in the same way so that the surface of the vanes of all 

 feathers may be seen to differ a great deal, if looked at under a microscope. 

 This may be illustrated by holding first a perfectly flat, smooth glass up to 

 the light and then a prismatic glass. The color-effects produced will be quite 



