88 THE SPECIES— ITS TAXONOMY, RANGE. BIOLOGY. & ECONOMIC IMPORTANCE 



gion is still mostly obscured by down and no pinfeathers appear on the median line of the 

 keel. Pinfeathers with downy tufts attached cover the back and rump from the neck to the 

 oil gland. These feathers have attained sufficient growth so that they are partially visible 

 through the downy fuzz. On the rump the tips of a few feathers are showing beyond their 

 sheaths. While the outer tail feathers are still in the pin stage, the central ones have emerged 

 from their sheathes. 



Four Ifeeks 



At this age adult primary number 10 is about half grown, number 9 is about one-third de- 

 veloped and number 8 is in the pin stage. Growth is complete in juveniles 7, 6. 5 and 4. 

 Among the secondaries the axial as well as numbers 2 to 10 inclusive are fully developed 

 while number 15 is well out of its sheath. 



The body of the bird in general appears well feathered in juvenile plumage. The side of 

 the head still appears downy. The pinfeathers on the chin also are obscured by down. The 

 juvenile feathers on the sides of the neck cover the downy area of the front median line of the 

 throat. The same is true of the feathers which cover the downy median line of the belly. 

 Numerous feathers are noted on the legs with those on the upper tarsus haxiiig downy tufts 

 appended. 



Five Weeks 



During the fifth week, although none complete their development, growth progresses rapid- 

 ly among the adult primarv feathers numbered 10. 9 and 8. Number 10 is now approxi- 

 mately the same length as the lunnber 2 juvenile secondary. Juvenile primar\ number 7, how- 

 ever, has been dropped and the tip of the adult feather is exposed. 



The bird now has a sleek appearance, having lost the fuzziness due to the many appendant 

 downy tufts which were prevalent during previous stages of development. Growth is complete 

 in many of the body feathers. The tail, however, is still growing. 



Six Weeks 



Among the flight feathers adult primaries number 10 and 9 have completed their growth 

 and number 6 has appeared as a pinfeather. Juveniles 5, 4 and 3 have also become com- 

 pletely developed. Among the juvenile secondaries, number 11 has completed its growth. It 

 should be noted particularly that two of the adult primaries have completed their develop- 

 ment before the juvenile primaries numbered 1 and 2 are half grown. 



The juvenile tail has completed its growth. 



Seven Weeks 



Though the flight feathers continue their regular growth, ihc only significant change in 

 feather replacement is the juvenile secondary number 12 which has completed its growth by 

 the end of the seventh week. Over the body in general the juvenile plumage is now com- 

 plete, with niost of the feathers very loosely htld in the follicles and released readily when 

 the bird i,~ handled. 



Evidence of the adult body j)lumage begins to appear in the form of pinfeathers according 

 to the regular succession outlined in the discussion of juvenile plumage. Some spaces and 

 areas adjacent to them are still comparatively bare with down remaining in most cases. 



