COLORS AND PLUMAGE OF BIRDS 45 



colored than the female, he takes on during the win- 

 ter a duller color similar to that of the female. Some 

 birds moult again in the spring, as in the case of the 

 brightly colored birds just mentioned, when the male 

 again acquires his bright breeding-plumage. Some- 

 times this moult is complete, sometimes only par- 

 tial. 



Change due to wear. A bird's color may also 

 change by wear and fading. The tip of a feather may 

 be of a different color from the rest of the feather, 

 and when this tip wears off, another color will be ex- 

 posed. When the male bobolink first moults in the 

 spring, it is of a yellowish color, due to yellow tips 

 on the feathers. In a few weeks these yellow tips 

 wear off exposing the black and giving the bird its 

 characteristic summer plumage. Other illustrations 

 are found in the snow bunting and red-winged 

 blackbird. 



Changes in color. The color of an individual bird 

 may change in accordance with two factors, age and 

 season. The plumage of the nestling is often differ- 

 ent in color from that which it later acquires. When 

 the male and female are differently colored, the 

 young usually resemble the female, as with the gold- 

 finch and scarlet tanager. In the case of the blue- 

 bird, however, the young birds have spotted breasts 

 and resemble neither of the adults entirely, although 

 even here the general color is similar to that of the 

 female. When the male and female are alike, the 



