AMERICAN ROBIN 207 



Occasionally a migrating flock flies in 

 and alights, it may be perching and cackling 

 noisily in the larger trees, or spreading out 

 upon the ground and running and chasing 

 actively. One such flock in the Garden, it 

 was estimated, numbered two hundred and 

 fifty birds. It came on April 10, 1907. One 

 of about twenty birds appeared on one 

 piece of lawn on April 8, 1905. And another 

 flock of similar size passed over in flight on 

 April 7, 1908. Other flocks at other times 

 have been seen. These appearances have 

 been an hour or two after sunrise, and, as 

 such flocks do not remain but rise again on 

 wing and depart, the occurrences are con- 

 firmative of the idea that the Robin is a 

 day-migrating bird. 



Toward the end of March or in early 

 April some female birds arrive, but it is well 

 on in the month of April before many fe- 

 males have joined the males and nest-build- 

 ing begins. Many nests have been built or 

 are building when May opens, but some 

 pairs prove to be even later in their home- 

 making. 



