Changes in Sex Composition 



Few data have been published relative to the sex ratios of prairie 

 chickens. Schwartz (1945:14) calculated sex ratios from birds seen 

 on booming grounds and found that only approximately 32 per 

 cent of the population were females. Davison (1940:58) found 

 a similar sex ratio in young of the lesser prairie chicken, and Lee 

 (1950:477) found, in the same species, a preponderance of young 

 males and old females in the bags of hunters in New Mexico. 



The percentages of females, of the greater prairie chicken, killed 

 by hunters in 1950, 1951 and 1952 in Kansas are given in Table 8. 

 Of nineteen captive chicks, from the Welda Area, nine were of 

 one sex and ten of the other, indicating a sex ratio at hatching of 

 near 50:50. Significant departures from this ratio occurred among 

 old females in 1950, but among young females the departure was 

 not significant for the size of the sample, but it was suggestive 

 of a differential mortality among young in favor of the males. The 

 sex ratio did not depart significantly from 50:50 in the sample ob- 

 tained in 1951 or 1952. It is not possible to say whether these dif- 

 ferences are real or result by chance from sampling, but there 

 seems to be but little doubt that, on the average, there are more 

 males than females of the greater prairie chicken. 



Differences in Abundance 

 as Indicated by Hunters' Success 



The success of hunters as an index to relative populations of game 

 has been used in Missouri since 1947 (see Crawford, 1951:307). 

 The method is theoretically sound, because the number of game 

 animals bagged in a given length of time, on the average, should 

 be related to the density of the population of game. 



In each hunting season ( 1950, 1951 and 1952 ) , hunters were in- 

 terviewed to ascertain the number of birds killed and the time 

 spent in hunting. The resulting data were computed in terms of 

 birds killed per gun hour, and are presented in Table 9. The dif- 

 ferences between each area sampled and between each year are 

 highly significant statistically in most instances. To test the value 

 of data on success of hunters we may first compare the results of 

 the three hunting seasons in the Welda Area where populations 

 were known. In 1950, hunters in the Welda Area killed, on the 

 average, 0.376 birds per gun hour, and in 1951, 0.128 birds per 

 gun hour. In 1952, too few birds were killed in the Welda Area 

 to permit comparison. These data compare favorably with the 

 populations of 145, 42 and 8 for 1950, 1951 and 1952 respectively 



[57] 



