110, 110, 108, 106, 102, 89, 77, 65, 45, 24 mm. long; capital tract with first- 

 winter feathers on coronal region, juvenal feathers elsewhere; dorsal and ventral 

 cervical feathers of first-winter plumage to anterior border of cervical apteria, 

 remainder of spinal tract completely of first winter feathers except juvenal 

 feathers interspersed in interscapular region; rectrices juvenal; upper tail- 

 coverts of first-winter feathers; undertail-coverts of juvenal feathers; ventral 

 tract with first-winter feathers meeting at midhne anteriorly, extending pos- 

 teriorly along superior margin to femoral tract; abdominal region with a few 

 first-winter feathers posteriorly, otherwise with juvenal feathers (see Plate 3, 

 Figure /); femoral and crural tracts predominantly of first-winter feathers; 

 pedals juvenal. 



Summary of Molt. — ^The postnatal and postjuvenal molts occur 

 in the same sequence. Juvenal primaries 1-7 are present at hatch- 

 ing and subsequently 8, 9 and 10 appear in that order. Juvenal 

 primary number 1 is molted at four weeks of age, and at tbat age 

 juvenal primaries 9 and 10 appear. Molt of the primaries proceeds 

 distally, and on the average one feather is molted in each wing 

 each week. Number 8 is molted at twelve weeks of age. Numbers 

 9 and 10 are retained through the first winter. The greater primary 

 coverts are replaced in the same sequence and approximately at 

 the same time as the corresponding primaries. 



Secondaries 3-13 are present at hatching, and all are present 

 in the juvenal plumage at the age of six weeks. The postjuvenal 

 molt of the secondaries begins with number 3 and proceeds proxi- 

 mally, but with more variation between individuals than there 

 is in the order of appearance of the primaries. Secondaries 2 and 1 

 are lost in that order when the postjuvenal molt of the primaries is 

 nearing completion at approximately ten weeks of age. 



At the time of hatching, the entire body, head and legs, excepting 

 the apteria, are covered with natal down. As a rule, in a molt, the 

 first feathers to appear in a given region are in the anterior or dorsal 

 part of that region, and growth proceeds posteriad and ventrad. 

 An exception to this is the cervical plumage which appears first 

 on the posterior part of the neck. Posterior dorsal feathers and 

 abdominal feathers appear over the entire region at one time. The 

 first feathers to appear on the body in a molt are the scapulars; 

 they are followed by the stemals, interscapulars and the femorals. 

 The capital, caudal and pedal tracts are the last to molt. The 

 rectrices seemingly are molted all at one time, or nearly so, since no 

 progressive loss of tail feathers is evident in any specimens at hand. 



Age Based on the Condition of the Molt 



Molt in the young of the greater prairie chicken is an orderly 

 process. On four occasions, greater prairie chickens, too young 



[36] 



