80 THE SFECIES~ITS TAXONOMY, RANGE, BIOLOGY, & ECONOMIC IMPORTANCE 



After the chick has dried off and takes its first furtive peek at the world from under the 

 wing of the mother, seven primaries may be counted. The longest of these usually has 

 approximately one-half inch exposed and a few will have about one-eighth inch of the feather 

 tip protruding from the sheath. None of the other three which make up the complement 

 are visible. While the average number of secondaries is 15, only nine are visible in the day- 

 old chick. Most of these have the downy tuft appended. The tail is represented by fuzz in the 

 form of longer drooping feathers. 



Juvenile Plumage 



The juvenile feathers begin to appear immediately after hatching led by two or three scap- 

 ulars which may be noted at four days of age. The flight feathers which are present at hatch- 

 ing, however, are functionally juvenile. 



When it occurs, the intermediate plumage represents a transition stage wherein the size and 

 number of the feathers are adapted to and conform with the progressive increase in size of 

 the bird. The feather which replaces the down develops in the same follicle and as it emerges 

 the latter is forced ahead of it. The downy tuft remains appended to the tip of the sheath 

 of the new feather. Unless it is broken off it remains attached until the sheath opens ex- 

 posing the lip of the developing feather. Thus the down with its elongated shaft and the new 

 juvenile supplement each other to afford the necessary protective covering for the body. 



It is evident, from studying feather succession, that the replacement follows a definite pattern 

 designed to afford the chick the greatest protection compatible with its habits at a given age. 

 Hence, the lungs, which are probably the most vulnerable organs of the young chick, are pro- 

 tected by the flight feathers, wings and rapid development of the scapulars (figure 7l. 1 he 

 latter merge with the back feathers and close over the back of the bird at about three weeks 

 of age. This coincides with the time it is being weaned from brooding by the mother. Coin- 

 cident with this growth, the feathers on the sides appear although these are obscured in the early 

 stages by the dense down. It is apparent that when the chick snuggles into the breast feath- 

 ers of the mother for warmth, the naked area over the lungs may be exposed to the maxi- 

 mum heat from her body. 



\\ hile there are certain exceptions, the pattern of succession in general is such that the 

 first feathers which appear cover and protect the base of those subsequently de\eloping. In 

 line with this, the emergence of the scapulars progresses tnuaid the rear from a point op- 

 posite the bend of the folded wing. These feathers also dext-lop laterally to merge with those 

 of the back at the base of the nape. Those of the sides develop from front to rear and 

 downward to cover the bases of the flank and upper IkIK feathers respectixely. The feath- 

 ers in the uj)p<'r rump region appear first, followed li\ those toward the rear which cover the 

 tail coverts. .Similarly the tail coverts attain sufficient length to cover the base of the tail 

 before the pin feathers in the latter appear. The flank feathers come in before those of the 

 thigh, while the appearance of the latter commences at the up|)er end of the leg. progress- 

 ing downward along the tibia and tarsus. These are feathered on the rear and front and 

 finally become closed in at the sides. On the belly, the succession has a tendency to spread 

 ill all directions. A bird at three weeks of age has a triangle of down extending backward 

 from the forward point of the keel, with its apex about midway to the pel\ is. This triangle 

 i-i bounded laterally by a fringe of juveniles. At the forward part of the belly this fringe 

 consists of onlv one feather on each side. Following to the rear on each side a pair appear, 

 then three rows and finally four rows where the two sides join at the midpoint on the keel. 

 Eight rows of feathers extend from here to the rear point of the keel. In the belly area the 



