14 ON BOSTON COMMON. 



as if nothing had happened. Not to be so 

 easily beaten, the man grasped the trunk again, 

 and shook it harder than before ; and this time 

 Collurio seemed to think the joke had been 

 carried far enough, for he took wing, and flew 

 to another part of the Garden. The bravado 

 of the butcher-bird is great, but it is not un- 

 limited. I saw him, one day, shuffling along a 

 branch in a very nervous, unshrikely fashion, 

 and was at a loss to account for his unusual de- 

 meanor till I caught sight of a low-flying hawk 

 sweeping over the tree. Every creature, no 

 matter how brave, has some other creature to 

 be afraid of ; otherwise, how would the world 

 get on ? 



The advent of spring is usually announced 

 during the first week of March, sometimes by 

 the robins, sometimes by the bluebirds. The 

 latter, it should be remarked, are an exception 

 to the rule that our spring and autumn callers 

 arrive and depart in the night. My impression 

 is that their migrations are ordinarily accom- 

 plished by daylight. At all events I have often 

 seen them enter the Common, alight for a few 

 minutes, and then start off again ; while I have 

 never known them to settle down for a visit of 

 two or three days, in the manner of most other 

 species. This last peculiarity may be owing to 

 the fact that the European sparrows treat them 



