6 GENERAL ECONOMY OF THE THRUSHES 



though such places are within the general area of distribution 

 of the respective species. They are insectivorous, like most 

 birds, in fact; but, like very many others that feed mainly upon 

 insects, they also eat berries and various other soft fruits. The 

 Eobin, for instance, is extravagantly fond of the berries of the 

 common Poke (Phytolacca decandra) ; and, during the season 

 when this fruit is ripe, specimens are often found with not only 

 the plumage, bill, and feet, but also various interior parts of 

 the body, dyed with the purple juice. The Thrushes are migra- 

 $ory in the United States. They are not properly to be con- 

 sidered gregarious, though some of them, like the Eobin, go 

 together in troops of hundreds at certain seasons. They are 

 arboreal in general habit; yet much of the time is spent on the 

 ground in the search for worms and insects. To illustrate the 

 case, again, in the instance of the familiar Kobin, every one 

 will recall the sprightly excursions of this bird on the green- 

 sward of our parks and gardens during the breeding-season, 

 and remember how swiftly it runs, with lowered head ; how it 

 then draws itself up at full length, displaying its trim and 

 shapely form to best advantage ; how then, satisfied that no 

 danger is to be apprehended, it tugs at the grub that lurks in 

 the roots of the grass, and finally bears it away to the nest, on 

 a bough of the nearest apple-tree. The mode of nesting varies 

 according to the species ; most of the Thrushes build upon 

 trees or bushes, but some, less ambitious, are content to nestle 

 on the ground. The order of their architecture is never elabo- 

 rate or ornate ; the nests, in fact, are rather rude, bulky, and 

 inartistic structures, more notable for strength and stability 

 than for beauty of finish ; they are built of leaves, grasses, 

 rootlets, and similar materials, often strengthened with mud. The 

 eggs are usually four, five, or six in number, blue or green in 

 color, with or without reddish spots ; some of the most closely- 

 allied species lay eggs distinguishable with as much certainty 

 as the birds themselves. Under favorable circumstances, two, 

 or even three, broods of young may be reared in one season. 

 The great voracity of young insectivorous birds is perhaps in 

 no case more strongly illustrated than in this group. If the 

 Robins were to feed all other seasons exclusively upon the fruits 

 of the orchard and garden, we should still remain in their debt 

 for the numberless thousands of noxious insects they destroy 

 during the period when they are rearing their young. The de- 

 stiuction of such useful birds cannot be too severely reprobated, 



