cervical region with only sheaths of new feathers; caudal tract as 

 follows: two outer left, four outer right and central left rectrices 

 old; all others new and of greater length medially. This is the only 

 specimen examined with partial molt of the rectrices. 



Summary. — The general pattern of the postnuptial molt seems 

 to be the same as that of the postjuvenal molt, especially of the 

 remiges. The body molt starts near the base of the wings, but 

 may occur rapidly and may be general over the body, with the 

 capital, caudal and pedal tracts being last as in the young. 



Length of Primaries as Correlated with Age and Sex 



Measurements were taken of primary number eight of each bird, 

 killed by hunters, examined in the open season, on October 24, 

 1951. This was to ascertain the amount of variation in the length 

 of this feather and to determine whether or not its length might 

 be used as a criterion of sex. Since the age class (adult or im- 

 mature) can be ascertained by the condition of the two outer 

 primaries, both sex and age could be ascertained from the wing 

 alone if it were possible to separate the sexes by this means. 

 Measurements were taken in milhmeters by placing the end of a 

 rule against the hind edge of the wing at the base of the feather and 

 flattening the feather against the rule. Data were obtained from 206 

 birds, and were recorded with the classification of each bird as to 

 sex and age. To aid in the interpretation of these data, wings 

 were saved from 23 birds, and measurements were made of both 

 the seventh and eighth primaries of these wings. 



Table 2. Length Characteristics of Primary Feathers of the Greater 



— s 



Prairie Chicken (cf. Fig. 11). X±2 —is the 0.9546 Confidence Limits 



n 



of the Mean; Sx is the Standard Deviation; V is the Coefficient of Varia- 

 tion; n IS THE Number of Individuals in the Sample. Extrexces of Length 

 ARE in Millimeters. 



Extremes _ « 



of X ± 2 — Sx V n 



Length " 



Primary 8 141-172 159.30 ± 3.74 8.99 5.64 23 



Primary 7 153-171 162.00 ± 2.54 5.45 3.77 23 



All males 138-178 166.29 ± 1.40 7.08 4.26 102 



Selected males 151-178 168.89 ± 1.14 5.72 3.43 99 



All females 98-178 158.41 ± 1.26 6.42 4.05 104 



Selected females 148-178 159.18 ± 1.10 5.51 3.41 100 



AU adults 142-178 163.78 ± 1.34 7.11 4.34 112 



All young 98-178 162.55 it 1.68 8.13 5.00 94 



[39] 



