HUNTING WITH A MICROPHONE 



711 



For five days the members of the expedition made continuous observations, through a pair of 

 powerful binoculars (pages 712 and 713). The camp at the base of this large oak was surrounded 

 by water, and palmetto fans kept the blankets out of the mud (page 706). 



laid the dust, but filled every depression 

 in the ground with water, including those 

 trodden by the cattle themselves around 

 the drinking vats that were normally kept 

 filled by windmills. Never before had they 

 seen standing water except in these vats 

 and never had they drunk out of anything 

 else. So now, with the vats in the center 

 of large ponds, they could be seen wading 

 out to them to get a drink. 



Each morning and again at evening dur- 

 ing the spring on the Davison Ranch, the 

 lesser prairie chicken cocks assemble in 

 groups of from four to forty on certain flat- 

 topped knolls in the shinnery to compete 

 with one another in a show of prowess, both 

 of voice and of bodily vigor (page 701). 



For six weeks the males engage in these 

 matches before the females intentionally 

 visit their gobbling grounds. Each male 

 comes back to exactly the same spot each 

 morning and gradually forces upon his 

 neighbors a respect for his territory, some 

 25 or 30 feet square. 



Many of the combats are mere gestures 

 or feints of anger, but others are sufficiently 

 severe to scatter feathers over the shinnery. 



Sometimes when the males jump at one an- 

 other and strike with their wings, a hap- 

 less bird is flipped clear over onto his back 

 by a stronger rival. 



Each morning from April 25 to ]\Iay 2 

 found us at the gobbling grounds of a group 

 of 26 males with the microphone staked 

 out in the territory of some aggressive cock. 

 Seven of the eight mornings the wind 

 howled in the microphone and the dust 

 blew, but at last it was quiet and we se- 

 cured a nearly perfect recording of the 

 birds' sounds, from the pattering of their 

 feet and the silken twitching of their tail 

 feathers to the loud gobbling that follows. 



COCKS ARE HEARD TWO MILES AWAY 



This gobbling is accompanied by the 

 swelling of the little balloons on the sides 

 of their necks, which serve as resonators. 

 These air sacs, really dilations of the esoph- 

 agus, swell up to the size of hens' eggs when 

 the mouth and nostrils are closed and air 

 is forced into them from the lungs. 



The sound itself is produced by the vi- 

 bration of tiny membranes in the syrinx, 

 or voice box, at the lower end of the wind- 



