EASTERN FIELD SPARROW 1221 



Later these feeding grounds were sometimes used by three or four 

 pairs, none of Avhich acted aggressively toward the others on it. Each 

 pair worked along the ground only a few inches apart while another 

 pair fed similarly a foot away. 



Courtshij). — After the male has sung steadily each morning for about 

 3 weeks during which he has established and defended his domain in 

 innumerable territorial squabbles, one morning a new bird appears on 

 it, the female for whom he has been waiting and singing. At first he 

 flies at her as if trying to drive her away, but she merely dives into a 

 bush and hides near the ground. When she reappears he may pounce 

 at here again, but still she does not leave, and his attitude quickly 

 changes to one of tolerance and then of acceptance. In a few hours 

 the two become inseparable, and as a rule they remain so for the entire 

 summer. 



The return percentage for females is much smaller than for males. 

 This is perhaps to be expected, for the male usually accepts the first 

 female that arrives on his territory. If his previous year's mate does 

 not arrive in time to mate with him a second 3''ear, she often settles 

 on a nearby territory with a new male, who may or may not have been 

 there the previous year. 



As soon as pairing is accomplished, the male sings much less often 

 and less vociferously. The change is so marked that I have usually 

 been able to tell which males are and which are not mated by their 

 singing behavior. For the next several days the two birds stay close 

 together. They fl}^ around the territory only a few feet apart, spend 

 much daylight tune feeding together, and they roost very close to one 

 another, usually in the same bush. The male continues to maintain 

 his territorial integrity closely, and chases every other field sparrow 

 that ventures over his boundaries. Sometimes he is extremely busy 

 indeed, tending his mate and fighting territorial battles with one or 

 possibly two neighboring males simultaneously. 



Pau-s start copulating usually during the nest-building period, from 

 2 to 5 days prior to egg laying. The act is generally performed early in 

 the morning. T^^pical were the actions of a female I watched working 

 on her nest at 7:00 one early May morning. Sitting on a low branch, 

 she crouched into the receptive stance, body held rather low across the 

 branch and head extended. The male trilled, fluttered carefully down, 

 mounted her for a few seconds, then flew away with rapid wingbeats 

 and trilling softly. She sat still a moment, then also flew away 

 chipping softly. 



Early one morning I watched another male copulate with his mate 

 on the ground and then fly to a far corner of his territory. After he 

 left his mate continued chipping softly and maintained her receptive 

 pose. A neighboring male flew across, copulated with her, and 



