54 



NORTH AMERICAN FAUNA 69 



the female, and the two would flutter together on the ground. 

 Sometimes the male stopped short of the female, and sometimes 

 when contact was made copulation did not take place. The female 

 sometimes responded with a faint tweet-tweet-tweet. Following 

 such an encounter, the male might fly off singing a song as loud 

 as the primary advertising song but not resembling it. These 

 flights were sometimes upward in a sort of spiral. One male I 

 watched often sang a whisper song after pouncing. Usually, how- 

 ever, the pair started feeding within a few feet of each other and 

 near the spot where pouncing occurred. Pouncing is also known 

 in the Red Warbler (Ergaticus ruber) (Elliott 1969, p. 188). 



Nice (1943, p. 174-175) reported Song Sparrow (Melospiza 

 melodia) pouncing as a form of courtship display "confined 

 typically to the early stages of the nesting cycle." The male flies 

 down to his mate, collides with her, and then flies away singing. 

 Nice states that pouncing by the Song Sparrow early in the season 

 has no immediate connection with copulation. 



Pouncing on the mate occurs during the long period while song is inhibited 

 and also during building. It may be a technique of the male for impressing 

 himself upon his mate during the time of silence, of making his presence 

 keenly felt. 



Howard (1929, p. 22) observed that after the sexual chase 

 recently paired Yellow Buntings (Emheriza citrinella citrinella) 

 flutter together on or near the ground or peck each other as they 

 rise in perpendicular flight, like fighting males. Howard believed 

 that the sexual chase and pouncing show that the male is ready to 

 copulate and that the female is not ready to receive him. 



One male that I watched for 2 days pounced about three times 

 each hour ; another that I watched for 3 days before the beginning 

 of nest building pounced about once every 10 minutes. A third 

 male pounced about once an hour on the day nest building began ; 

 nest building was sporadic that day and occurred mostly in the 

 morning, for just 2 or 3 minutes following pouncing. 



Copulation occasionally occurs while the female is perched on a 

 limb of a shrub or tree. When copulating in this manner the male 

 sometimes holds onto the female's crown feathers. 



NESTING BEHAVIOR 



Nesting period 



The prenesting period for paired Swainson's Warblers is rela- 

 tively brief, for nesting begins soon after pair formation. For 

 example, I visited the breeding grounds in the Dismal Swamp on 

 April 12, 1969, at which time the Swainson's Warblers had not 



