Vol i907 IV ] Wood, Autumn Warbler Migration. 323 



thick timber as you follow down the river, there being only a grove 

 between this point and the Detroit River. The bulk of warblers 

 came down this water-way and during the earlier part of the season 

 continued to the grove from whence they must have turned south, 

 as further progress was barred by the Detroit River. 1 Later, 

 however, my piece of timber was the limit of their eastern move- 

 ment and they went due south from here to a large piece of thick 

 woods. This was the program in 1905 except from September 20 

 to October 5 when they went southwest to follow a chain of large 

 woods that extended far southward. The lesser number of war- 

 blers came from the northeast and had evidently followed the 

 Detroit River. During September about twenty-five per cent, were 

 apparently not migrating but taking life easy and remaining in the 

 woods. I suppose these were the main night travelers and if so, 

 when do migrating warblers sleep? All seen by me exhibited the 

 characteristic activity of the family. We all know that large 

 numbers travel by night, but who has seen them asleep during the 

 day? Judging from my experience with night migration, they 

 sleep from about 11 p. M. to 4 A. M. Of course, I really know 

 nothing positively, and my belief is based only on the fact that the 

 birds were not heard calling between the above mentioned hours, 

 and on the actions of a captive Indigo Bunting (Cyanospiza cyanea). 

 This bird was not over a month old when trapped in the summer and 

 soon showed no desire to escape from its cage. It appeared con- 

 tented, and slept peacefully all night until the advent of the fall 

 migration; even then, there was no change in the day time, but 

 soon after dark it became restless. The performance began with 

 a hopping to and fro on its perch with frequent pauses to partly 

 squat, as if about to spring into the air. At the first call note of a 

 passing migrant it uttered a sharp metallic chirp and flew about 

 the cage, making frantic efforts to escape and, when somewhat 

 exhausted, climbed parrot-like about the cage top trying to force 

 its head between the wires. Toward midnight it quieted down 

 and slept a few hours but became active before daylight. This 

 dominating influence ceased suddenly the latter part of October, 



1 It is an interesting fact that while the Warblers came down this water-way two 

 thirds of the Robins took the reverse course. They mainly came from the east and 

 had probably crossed the Detroit River, but several large nights came from the south. 



