THE INVITATION. 283 



branches, uttering a sharp, preliminary chirp. 

 I followed it with my eye ; saw it mount into 

 the air and circle over the woods, and saw it 

 sweep down again and dive through the trees, 

 almost to the very perch from which it had 

 started. 



As the paramount question in the life of 

 a bird is the question of food, perhaps the 

 most serious troubles our feathered neigh- 



o 



bors encounter are early in the spring, after 

 the supply of fat with which nature stores 

 every corner and by-place of the system, 

 thereby anticipating the scarcity of food, 

 has been exhausted, and the sudden and 

 severe changes in the weather which occur 

 at this season make unusual demands upon 

 their vitality. No doubt many of the earlier 

 birds die from starvation and exposure at this 

 season. Among a troop of Canada sparrows, 

 which I came upon one March day, all of 

 them evidently much reduced, one was so 

 feeble that I caught it in my hand. 



During the present season, a very severe 

 cold spell the first week in March drove the 

 bluebirds to seek shelter about the houses 

 and out-buildings. As night approached, 

 and the winds and the cold increased, they 

 seemed filled with apprehension and alarm, 



