OF ARTS AND SCIENCES 107 



183. Hylocichla ustulata swainsoni. Olive-backed 



Thrush. 



A very common summer resident in all damp woodland 

 from the valleys up the mountain sides to almost the limit of 

 tree growth, where it becomes in smaller numbers a companion 

 of the Bicknell's Thrush. It occupies the damper portions of 

 the mountain slopes. Thus on Boy Mountain the voice of the 

 Olive-back is rather infrequent on the southern, sunny side, 

 while it is much heard on the northern slopes. In the fifty-acre 

 piece of Highland woodland four or five pairs are usually found 

 in the portion near the river. The species is abundant along 

 the road following the South Branch and extending up into 

 Jefferson Notch. Here nearly fifty singing birds have been 

 recorded, when we have taken the drive leisurely, and on June 

 21, 1907, seventy-one singing birds were recorded on this drive 

 continued through Bretton Woods and over the Cherry Moun- 

 tain road. 



In recent seasons the song has been regularly heard in the 

 woodland opposite our house, where formerly the voice of the 

 Hermit only had reigned, but where now is heard also a voice 

 or two of the Wood Thrush. The song period usually extends 

 through July and but seldom into early August, the latest hear- 

 ings having been August 5 in 1907 and August 7 in 1900. The 

 call-note continues to be heard occasionally throughout August 

 and to late September. Some birds are present in early October, 

 the eighth day in 1904 furnishing the latest record. 



184. Hylocichla guttata pallasi. Hermit Thrush. 



A common summer resident, seeming quite as numerous 

 about the Highland as the Robin and in some seasons more 

 numerous. The song period reaches without interruption to the 

 middle of August. In 1910 three birds had continued to sing 

 on the Highland in the early morning up to August 15 inclusive. 

 On the following day I could hear neither bird, and I did not 

 hear the song again. In the two years next preceding the song 



