the booming-season. Yeatter (1943:385), on the other hand, found 

 that breeding in IlHnois was spread more uniformly over a period 

 of time and concluded that this was because all of the birds did 

 not attain sexual readiness at the same time. 



Schwartz (1945:53) observed that males remain in their in- 

 dividual territories, on the booming ground, and allow matings in 

 adjacent territories to proceed without interruption only at the 

 height of the breeding season. At other times, males frequently 

 interrupt matings in adjacent territories by driving the male from 

 the back of the female. This is not to imply that all matings occur 

 at the height of the season, for courtship and matings occur at 

 places other than the booming ground, and the spread of hatching 

 dates, including those of re-nestings, indicates that matings occur 

 over at least a six-week period of time. Both sexes seem to be- 

 come physiologically incapable of breeding shortly after the first 

 of June. This characteristic is most significant, because it limits the 

 reproductive period to late spring and early summer, and makes 

 the success of reproduction largely dependent upon the favorable 

 weather within this short period. Bobwhite quail, on the other 

 hand, remain paired throughout the summer, and have been known 

 to hatch young as late as October. Frequently the main hatch 

 of bobwhites occurs in July. In Missouri, the peak of hatching in 

 quail was in the first half of July in 1948, in the last half of July 

 in 1949, and between July 7 and August 7 in 1950 (see Stanford, 

 1950 and 1951 ) . The value of the ability thus to persist in nesting is 

 obvious, in that it tends to insure a high reproductive rate even 

 though weather conditions may be unfavorable for nesting and rear- 

 ing young in the first part of the summer. 



Nesting 



To find nests and broods of the greater prairie chicken, a flushing 

 device designed after that of Lehmann (1946) was made to be 

 used on a light truck, tractor or jeep. The essential feature of this 

 device was a drag suspended from a horizontal bar that was 

 mounted on the vehicle. The horizontal bar was made of steel 

 pipe in three sections, each ten feet long, the outer two of which 

 telescoped into the center section. A central post provided means 

 of supporting the ends by wires. It was found necessary to use 

 springs in the supporting wares to prevent breakage. The most 

 satisfactory drag was made of pieces of steel pipe the same length 

 as the sections of the horizontal bar. Figure b of Plate 4 illustrates 

 this device mounted on a truck. Later, two sections were added 

 making a total spread of 46 feet. This bar on a hght tractor was 



[24] 



