5O LIFE-HISTORIES OF BIRDS 



to ascertain the effect of such treatment. He, 

 therefore, fastened a lath over the aperture of the 

 can, and retired to a short distance to watch the 

 result. The birds went to work, and by their per- 

 severing efforts, the piece was soon dislodged. All 

 hindrances being now out of the way, they applied 

 themselves diligently to work, and in a short time 

 raised a brood of five young birds. On this occa- 

 sion it was discovered that the young were fed 

 almost exclusively upon the larvae of Pieris olera- 

 ce<z, P. rapce, and the wingless bodies of Spilosoma 

 Virginica. 



The eggs of the Blue Bird are usually four in 

 number; sometimes we have observed nests with 

 five. They are of a uniform pale blue, measuring 

 about .82 of an inch in length by .61 in breadth. 



After the breeding period is over, preparatory 

 to migration, the birds collect in small parties and 

 feed indiscriminately upon the seeds of Panicum 

 capillare, Poa annua, berries of Juniperus Virgini- 

 ana, diptera, and the larvae and imagos of small 

 lepidoptera. They are now more arboreal than 

 in the spring, frequenting small trees and bushes, 

 but are never known to seek the topmost boughs 

 of lofty trees. 



Among the earliest of our vernal migrants, they 

 are among the latest to return in the autumn. 

 Their departure is quite variable, depending upon 

 climatic and dietetic causes. During unfavorable 

 autumns, their presence has been missed by the 

 last of September; but, when the weather has been 



