ICTERID.E 



245 



rightful lu-irs dwindle ;i\vay and ])crisli. In 

 some cases the vouns,' L owhird claims all the 

 time of the foster-mother during the day, so that 

 her own eggs become chilled and dn imt hatch; 

 in others the eggs of the foster-parent are punc- 

 tured, apjKirently by mother Cowbird. If, after 

 all, any of the rightful occupants of the nest 

 survive, the young Cowbird, taking the middle 

 of the nest, grows so much faster than they that 

 it crowds them out and thus, by hooU or by 

 crook", soon has the nest to itself and receives 

 all the food that should have nourished an inter- 

 esting family. In the meantime it has grown so 

 strong and well-feathered that in about seven 

 days after it leaves the shell it has outgrown 

 the nest and climbed out upon the branches. Later 

 it follows its foster-parents about, begging for 

 food. It is a common sight to see a small Spar- 

 row or Warbler feeding a young Cowbird almost 

 twice its size. The big clown looks as if it 

 might swallow the little bird which ventures to 

 plunge insects and worms into that gaping, capa- 

 cious, clamoring throat. .\t last the young Cow- 

 bird, being well grown, well feathered, and more 

 than able to take care of itself, searches out the 

 care-free flocks of its kind, joins one of them, 

 and the troubles and cares of its foster-parents 

 are over for the season, unless they attempt to 

 rear a second brood, when the story may be 

 repeated. 



Another interesting j^henomcnon about the 

 Cowbird is its close association with cattle. As it 

 ranges over a large part of North America and 

 well into Mexico, and as it feeds much on in- 

 sects found in grass land, it uses the cattle as 

 dogs to flush its game. Wherever cattle feed, the 

 Cowbird may be found. It may be seen more 

 commonly in the West than in the East, around 

 and close in front of the cattle, as they graze, 

 chasing and catching insects which flee from the 

 towering kine. The Cowbird passes freely be- 

 neath the cow's belly and even alights on her 

 back to seize the insect parasites, flies, etc., that 

 find harborage there, .\pparently the Cowbird 

 rarely associates with horses, sheep, or swine but 

 gives its attention chiefly to cattle. In this re- 

 spect it resembles the introduced Starling, the 

 Rhinoceros Bird, and a few other notable species 

 which seek the company of certain large animals. 

 The Cowbird, however, is not confined to the 

 pasture but visits garden, field, wood, and orchard 

 and often roosts in the marsh, flocking with the 

 Blackbirds. 



This species remains quite late in the north 



and flocks have been seen in winter in southern 

 .\ew bmgland. but the greater mmiber winter in 

 the Southern .States where they feed much in the 

 neighborlujod (jf water. 



Edw/XKI) Ilovvi; Fokrusii. 



The food of the Cowbird has been carefully 

 studied and the tabulated results prove that were 

 its food-habits alone to be considered this bird 

 would have to be ])laced among the beneficial 

 rather than the harmful s])ecies. But it nuist 

 not be forgotten that in causing the death of 

 multitudes of small birds, all of which are val- 

 uable to the agriculturist, the Cowbird is doing 

 an injury for wliich his beneficial work in other 

 directions can hardlv atone. The lives of two to 



Photo by H. K. Job tj.urtesy ot Uuting Pub. Co. 



NEST OF CHESTNUT-SIDED WARBLER 

 Containiag a young Warbler, an egg, and a young Cowbird 



five other young birds is the price of each Cow- 

 bird. About 22 per cent, of its food is animal 

 matter and 78 per cent, vegetable. It appears to 

 eat few beneficial insects, avoiding the predacious 

 ground beetles, but eating a few wasps, bees, 

 and ants. Its best work is in destroying grass- 

 hoppers. It also eats boll weevils and caterpil- 

 lars, the latter including cutworms and army- 

 worms. Contrary to expectation it eats few flies 

 or maggots, and there is no proof that it eats in- 

 testinal worms from cattle droppings or ticks 

 from the animals themselves. 



The Cowbird does no harm to cultivated fruits. 

 Its vegetable food consists mainly of weed seeds 

 and grain, the former predominating and the 

 latter being largely wa.ste. 



In Mexico, Lower California, and the adjacent 

 parts of the United States, there is found a small 

 edition of the Cowbird, which is called the Dwarf 

 Cowbird (Molothrus atcr obsciinis). 



