674 ULIVE-BACKED THRUSH. 



DESCRIPTION OF NESTS AND EGGS. 

 Nests, composed of weeds, grasses, mosses and hemlock twigs woven tijgethcr, furiiiinsf a neat, r.-itlier 

 compact, well proportioned structure, which is lined with fine roots and soft mosses. Dimensions. E,x- 

 ternal diameter, 4.50 inches ; internal, 3 inches; external depth, 2.50 inches : internal, 1.75 inches. Eugs, 

 usually four in number, blue in color, of varying shades, spotted and blotched throughout with pale violet 

 and brown. Dimensions, .90 by .61 to .!I5 by .65. 



HABITS. 



While migrating, this thrush is very generally t'ound in swampy localities, where it is 

 extremely shy, keei)ing in the densest thickets. Here it maintains perfect silence, except 

 an occasionl soft chirp of alarm. It also spends the greater part of its time u])()n the ground 

 scratching among the leaves in search of its insect food. It is extremely difficult to pro- 

 cure a specimen, as upon the approach of the intriider it instantly hides or flits rapidly 

 through the bushes, pausing hut an instant here and there to glance at its enemy. If driv- 

 en into a thicket it will persistently remain concealed until a])i)roached tjuite nearly, and 

 then rapidly move to another place but a few rods away. If too closely' pursued it rises 

 suddenly to the tops of the bushes, and darting througli the woods, with nearly the speed 

 of light, disappears in the distance. This spe<ues pas.ses tln-ough our midst in great num- 

 bers ; yet, on account of its retiring habits, only tlie experienced collector will consider it 

 a,t all common. Those who have never seen it on its breeding grounds, and who can judge 

 of its habits only diu'ing the migrations, will consider it a silent and mysterious bird. 



But let such an one visit its northern home, when the mild l)reezes of June sigh 

 quietly through those vast primeval forests that everywhere cover the land. Let him 

 wander beneath the dark shadows of the huge hemlocks and spruces, the large limbs of 

 which form immense arches high overhead. The air is filled with the balmy odor of their 

 leaves, mingled with the spicj' fragrance of the snowy Howered moosewood. The groujid 

 is covered with a soft carpet of green moss, and all the plants that grow in these shady 

 retreats are now in bloom, while the gentle murmur of some mountain stream is heard, 

 harmonizing pleasantly with the warbling of tlie birds. Preeminent among these the 

 echoing song of the Olive-backed Thrush rings through the wooded valleys, enchanting 

 the ear with its scarcely surpassed melody. The song diflers entirely from that of the 

 Hermit Thrush, being more continuous but not quite as loud. It is, however, remarkably 

 fine, and one can hardly believe that the silent bird he has been accustomed to see farther 

 south is capable of producing such delightfid notes. Not only in the newly acquired vocal 

 powers does the bird in summer difler from the same species iii spring and autunni, but its 

 habits are different. It does not now skulk in the bu.shes, but perches vipon the branches 

 of its fixvorite evergreen trees, many feet from the groimd, and at this elevation sings its 

 song. It has, however, the same low soft chirp of alarm, but it uses it oftener, boldly 

 standing in plain sight while it thus remonstrates with the invader, as if conscious of a 

 ])rior right to the soil. While in this position it usually moves its tail slowly, and tips its 

 head slightly while it gazes, with its full round eye, upon the movements of the invader. 

 Sometimes, however, it will sit witliont nois^e or motion, after the manner of the Rol)in, 

 until one has passed quite under it. At such times it is difficult t(j detect the birds, so 

 closely do its colors bleiul witli tho.'^e of the trunks and branches of the trees. These 



