6 TURD US SWAINSONII. 



The song of the Robin consists of several loud notes given with energy ; it can hardly be 

 called fine, yet it is lively and agreeable. Perched on the topmost bough of some apple tree, 

 in the rosy twilight, after a sunny day in early spring, he pours out his song. Thus his simple 

 lay becomes associated with the balmy odor of the piue woods, the budding trees, and growing 

 grass in the meadows, all pleasant reminders of the coming summer. 



TUKDUS SWAINSONII. 



Olive-backed Thrush. 



"Turdns Swainsonii CAB. in Tschudi, F. Peruaua, 1844-46, 183." BAIRD, Birds of North America, 1858, 21G. 

 Tnrdus Alicia BAIUD, Birds of North America, 1858, 217. 



DESCRIPTION. 



SP. CH. Form, not very robust. Bill, rather short and stout. Tongue, narrowing towards the terminal half; 

 bifid and fringed for about one-third its length. Breadth of sternum generally exceeding the depth of the marginal 

 indentations. 



COI.OK. Adult. Above, uniform olivaceous brown, varying somewhat in intensity. Under parts, white, with the 

 chin, throat, upper part of breast, eyelids, sides of head, and a stripe in front of the eye, more or less tinged with 

 rufous. The throat and breast are also spotted with dark brown and olivaceous. These spots, which vary in 

 number and size, are darker on the upper, and lighter on the lower part of the breast. Flanks, olivaceous. Under 

 tail coverts pure white, with the edges occasionally tinged with olivaceous. Under side of tail and of wings, 

 olivaceous, with a pale buff bar starting from the inner edges of the latter and extending across them. Iris and 

 feet, brown. Bill, dark brown, with the base of the lower mandible pale yellow. 



Specimens vary much in intensity of coloration; sometimes the rufous of the head, neck, and breast, will be 

 nearly obsolete, being represented only by a pale buff tinge; from this stage I find, in specimens now before me, a 

 gradual transition to a bright rufous infusion of these parts. The back, as has been remarked, also varies In 

 Intensity of shade, from a dark olivaceous to a more reddish brown. This change of color on the upper parts does 

 not always accompany that of the lower. For example ; one of the palest breasted birds which I have, has the 

 most rufous back; while a specimen with a very red breast is much paler on the upper surface. The line in front 

 of the eye is more strongly marked in some specimens than in others. Individuals also have a decided reddish or 

 purplish tinge on the outer edges of the quills and tail feathers. Sometimes the feathers on the top of the head have 

 darker centres. 



Young with two bars on the wings formed by the yellowish tips of the coverts. Lesser wing coverts with light 

 central stripes to the feathers. The extreme ends of the wing and tail feathers are sometimes narrowly tipped with 

 white. The bars on the under sides of the- wings are more extended and better defined than in the adult. 



Ncstimj plumage. The following description is taken from a young bird in this plumage, kindly loaned me by my 

 friend, William Brewster, and it is the only one I ever saw in this stage. General colors above and below, similar 

 to the adult. The centre of each feather on the entire upper portion, however, has a stripe of rufous, which widens 

 at the extremity. The triangular spots on the wing coverts are much more prominent in this stage than in the last. 

 The spots on the breast are somewhat broader, on account of the webs of the feathers not being as closely blended 

 as in the adult. The bar beneath the wing is perhaps wider, the colors being more diffused. The bill and feet 

 are paler. 



OBSERVATIONS. 



This species may be distinguished from all others by the uniform olivaceous color of the back and tail. T. 

 fuscescens is uniform on the upper parts, but the color is reddish. The spots on the breast of the latter species are 

 also smaller and more restricted. Stcainsonii differs from Pallasii, another closely allied species, in having the back 

 and tail uniform ; the tail of Pallasii being much more rufous than the back. The Olive-backed Thrush is distributed, 

 during the breeding season, throughout that section of North America that lies between latitude 44 and the Arctic 

 Ocean. A few winter in Florida, but the greater part pass into South America. 



DIMENSIONS. 



Average of twenty-eight specimens. Length, 7-14; stretch, 11-84; wing, 3-79; tail, 276; bill, -33; tarsus, 1-14. 

 Longest specimen, 7-76; greatest stretch of wings, 13-00; greatest length of wing, 4-40; of tail, 4-00; of bill, >-">; 

 of tarsus, 1-30. Length of smallest specimen, G-54; smallest stretch of wings, 10-50; smallest length of wing, 2-70; 

 of tail, 2-10; of bill, 47; of tarsus, -98. 



DESCRIPTION OF NESTS AND EGGS. 



The Nat is composed of weeds, grasses, mosses and hemlock twigs woven together, forming a neat, rather 

 compact, well proportioned structure, which is lined with line roots and soft mosses. Dimensions. External diameter, 

 4-50 inches; internal, 3 inches; external depth, 2 50 inches; internal, 1-7 ~> inches. 



The Eijgs are usually four in number, blue in color, of varying shades, spotted and blotched throughout with 

 pale violet and brown. Dimensions. -OOx-Gl to -95x-(i5. 



