A 2 Wood & Frothingham, Birds of Ah Sable Valley. [fan! 



the water. Lenticular islands are of frequent occurrence wherever 

 logs or stumps have lodged in the channel. 



A noticeable change is to be observed in the tree life of the river 

 as one passes from Crawford and Oscoda counties into the lower 

 waters of Alcona and Iosco counties. Here a gradual increase 

 may be noted in the areas covered by willows and poplars, while 

 swamp oaks, hard and soft maple, and hemlocks tend to replace 

 the soft woods of the cedar swamps. This change in the charac- 

 ter of the vegetation is probably due to the varying proportions of 

 high and low lands, the latter, as is usual in the lower and older 

 parts of a river valley, increasing in amount toward the mouth 

 of the river. 



The accompanying list of 103 species of birds, in which Mr. 

 Wood's and my notes have been incorporated, was taken from the 

 notes made during each excursion, and thus represents more or 

 less completely the bird life of the valley, for the period from June 

 13 to September 22. — E. H. F. 



The observations and data which I have contributed to the fol- 

 lowing list were made during two trips on the river in the summer 

 of 1903. The first trip was made in search of the Kirtland Warbler 

 for the University Museum, 1 and extended down the South Branch 

 from Roscommon to the Au Sable, and as far as Big Creek in 

 Oscoda County. This is about seventy miles, by river, from 

 Roscommon. My notes on this trip cover a period of sixteen 

 days, from June 30 to July 16, and therefore at a time when most 

 of the birds were breeding, or feeding young. This gives us a 

 list of the summer residents. 



My second trip was made in company with Professor J. E. 

 Reighard. On the morning of Sept. 6, we started down the Au 

 Sable River from Grayling in a boat to make a survey of the life 

 in and along the river. This trip occupied fifteen days and cov- 

 ered a distance of about one hundred miles in a straight line, or 

 about three hundred by the river. 



Grayling is a small town of about 1500 inhabitants, and is situ- 

 ated in the western part of Crawford County, Michigan, on the 



1 Bull. Mich. Ornith. Club, Vol. V, pp. 1-13. 



