OLIVE-BACKED THRUSH 177 



scribed in some detail by Dr. Lynds JoDes (1910) and by Tavern er 

 and Swales (1908). 



What few banding records are available seem to indicate that sub- 

 stantially the same route is followed on both migrations while the 

 birds are passing through some parts of the United States. Mrs. 

 Arch Cochran (1935) reports that she banded two olive-backed 

 thrushes at her banding station in Nashville, Tenn., on May 15, 1932. 

 On September 18, 1932, both returned and were taken in the same 

 trap. On May 30, 1933, one of them returned to the same location; 

 and it was captured again on September 24, 1933, in the same trap. 

 At least a part of the same route was followed on each of four migra- 

 tions, an interesting record. (See remarks under "Fall.") 



Nesting. — Practically all the nests of the olive-backed thrush found 

 by my companions and me in northern New England were in spruces 

 or balsam firs; of those recorded in our notes, 11 were in spruces and 

 10 in balsams; they were almost always in small trees where the forest 

 growth was more or less dense; the height from the ground varied 

 from 2 to 20 feet, but only two were above 7 feet; the nests were usually 

 bulky and well made and were generally built on two or more hori- 

 zontal branches and close to the trunk, though occasionally one was 

 about two-thirds of the way out on a branch. Dr. Brewer (Baird, 

 Brewer, and Ridgway, 1874) gives a very good description of the nest, 

 as follows: "The nests average about 4 inches in diameter and 2 

 in height, the cavity being 3 inches wide by about 1% deep. 

 They are more elaborately and neatly constructed than those of 

 any other of our thrushes, except perhaps of T. ustulatus. Conspic- 

 uous among the materials are the Hypnum mosses, which by their 

 dark fibrous masses give a very distinctive character to these nests, 

 and distinguish them from all except those of the T. ustulatus, which 

 they resemble. Besides these materials are found fine sedges, leaves, 

 stems of equisetaceous plants, red glossy vegetable fibres, the flowering 

 stems of the Cladonia mosses, lichens, fine strips of bark, etc." 



Six nests before me measure externally 4 to 4.5 inches in diameter 

 and 3 to 3.5 in height; the inner diameter varies from 2.25 to 2.5 and 

 the depth of the cavity from 1.5 to 1.75 inches. They vary consider- 

 ably in general appearance and in composition. One very compact, 

 dark-colored nest is made up largely of fine spruce or tamarack twigs, 

 carried up the sides and into the rim, mixed with grasses, strips of 

 weed stems, and black and green lichens; it is lined with dead leaves. 

 Another is made almost wholly of grasses and weed stems, with only a 

 few very fine twigs in the base; this is lined with skeletonized leaves 

 and lichens. Three others are more or less intermediate in construc- 

 tion between the above two. A fifth is made largely of strips of the 

 inner bark of the cedar, mixed with black rootlets and much rotten 



