23^ 



BIRDS OF AMERICA 



ing, " Help ! Murder ! Get out ot here or we'll 

 knock your head off !" Whenever I visited the 

 Thrush's home, the mother stayed on the nest 

 until I almost touched her, then she slipped 

 through the branche.- with a low whistle for her 

 mate. He was near at hand. They were 

 anxious, but they did not relieve their feehngs 

 with a great noise and fuss, as the Robins did. 

 The Robins are noisy ; the Thrushes shy and 

 quiet. 



As I watched each time the Thrush mother 

 came to feed her young, she lingered at the nest 

 edge. I often saw her sit for several moments 

 at a time looking at her babies and caressing 

 them with a real mother's love. 



\\'lLLI.\.\r L. FiXLEY. 



While this Thrush is very fond of fruit, its 

 partiality for banks of streams keeps it from fre- 

 quenting orchards when they are far from water. 

 It is most troublesome during the cherry season, 

 at the time when the young are in the nest. It 

 might be inferred from this that the nestlings 

 are fed on fruit, but such is not the case to any 

 noticeable extent. The parent birds eat the fruit 

 themselves, while the young, as is usual with 

 nestlings, are fed mostly upon insects. The old 

 birds eat some fruit throughout the season, but 

 do not seem to attract much attention bv their 



depredations on prunes and the later fruits. As 

 the Thrush is one of the " soft-billed " birds, its 

 attacks on fruits are limited to the thin-skinned 

 varieties. It is as often seen on the ground peck- 

 ing at fallen fruit as attacking the cherries on 

 the trees. It probably confines its depredations 

 upon the later fruits to such as have already been 

 broken into by stout-billed birds. 



This Thrush is an efificient destroyer of in- 

 sects, and during its sojourn in the fruit region 

 a little more than half of its food consists of 

 harmful insects. In the investigation of this 

 bird's diet 157 stomachs were examined and 52 

 per cent, of animal matter to 48 per cent, of 

 vegetable was found. The animal portion was in- 

 sects, spiders, earthworms, sowbugs, beetles, 

 caterpillars, ants, wasps, and grasshoppers. The 

 vegetable portion in addition to the skins and 

 pulp of cherries contained seeds of blackberries, 

 raspberries, elderberry, pepper tree, and weeds. 



In its insect diet the Russet-backed Thrush is 

 almost wholly beneficial, as it eats but few pre- 

 dacious beetles or other useful insects. As young 

 Thrushes are fed almost exclusively upon in- 

 sects and as they eat almost continuously from 

 morning till night, they must destroy an enor- 

 mous number of these harmful creatures. The 

 Russet-backed Thrush must be considered as one 

 of the positively beneficial birds. 



OLIVE-BACKED THRUSH 



Hylocichla ustulata swainsoni (Tscliiidi) 



.\. O. U. Xumber 758a 



Other Names. — Alma's Thrush ; Swainson's Thrush ; 

 Swamp Robin. 



General Description. — Length. 7'4 inches. Upper 

 parts, olive-brown ; under parts, white and buff with 

 spots of olive-brown. Bill, about lA length of head, 

 slender, gradually and increasingly curved downward 

 toward the tip ; wings, rather long and pointed ; tail, 

 not more than ■)4 length of wing, slightly notched, the 

 feathers slightly sharpened at the extreme tip; legs, 

 long and slender. 



Color. — Above, uniform grayish oUvc-hrown; con- 

 spicuous eye-ring and lores pale buff; sides of head, 

 olive-brown, with narrow streaks of pale buff; cheeks, 

 buffy streaked with olive-brownish; chin, throat, and 

 chest, buff ; the chin and throat sometimes buffy-white ; 

 the sides of lower throat and whole chest with wedge- 

 shaped marks dark olive-brown ; these marks narrower 

 and darker in front, broader and lighter behind, those 

 on central part of chest sometimes sooty-blackish and 

 usually on a cream-buff ground color ; a streak below 

 cheek of olive-brown along each side of throat; breast, 

 abdomen, and under tail-coverts white ; the upper por- 

 tion of the first transversely spotted with olive-brown ; 

 sides and flank, grayish-olive ; bill, dusky brown ; the 



Sl-c Color Pl.ltc 105 



basal half below pale dull flesh color; iris, deep brown. 



Nest and Eggs.— Nest: In a bush or small tree, 

 usually from five to eight feet from ground, in secluded 

 situations; composed of grasses, leaves and shreds of 

 bark; in the more northern parts of the bird's range, 

 moss enters frequently into the nest construction. 

 Eggs: 3 or 4, with a ground color of greenish-blue, 

 speckled with varying shades of reddish-brown, rufous, 

 or light umber-brown. 



Distribution.— North America in general except 

 Pacific coast district south of Cross Sound and Lynn 

 Canal; breeding from Massachusetts (Berkshire County. 

 2000 to 3500 feet), mountains of eastern New York 

 (Catskills), Pennsylvania, and West Virginia (spruce 

 belt), northern Michigan, Colorado (Rocky Mountains). 

 Utah (Uinta and Wasatch mountains), Nevada 

 (East Humboldt Mountains), and California (Sierra 

 Nevada) northward to Alaska (Kenai Peninsula; 

 Iliamna District; Yukon valley; Kowak valley, etc.), 

 Yukon Territory (Dawson, Lake Marsh; Lake Lebarge ; 

 Caribou Crossing), ]\Iackenzie and shores of Hudson 

 Bay ; in migration southward over whole of Mexico 

 and Central America to Peru, Brazil, and Argentina; 

 occasional in Bermudas and Cuba. 



