342 THE BIRDS OF MAINE 



confines of civilization, though rarely found along rivers in the 

 wilderness. The fall departure begins in September and about 

 all are gone by the middle of October, though exceptionally 

 the species has been recorded as late as December twenty- 

 seventh. 



Small scattered groups may be seen in the barnyards and 

 pastures during the period of their stay here. They feed on 

 flies, ticks and an equally great variety of the insects found in 

 barnyards and pastures, also various weed and grass seed, grain 

 and berries, usually waste grain and wild fruits and berries 

 being taken rather than material of any value in that line. 

 Consequently as far as food goes the species is beneficial, but 

 when it comes to a consideration of its breeding habits this 

 balance is offset and we must finally place the species down as 

 injurious and undesirable. 



The female builds no nest of her own but lays her eggs in 

 the nests of other birds, preferring the nests of the smaller 

 Sparrows and Warblers such as Song Sparrow, Chipping Spar- 

 row, Vesper Sparrow, Savannah Sparrow, Yellow Warbler, 

 Myrtle Warbler, American Redstart, Chestnut-sided Warbler, 

 Catbird, Wilson's Thrush, and in fact the nests of almost 

 every species of our smaller birds to which they can obtain 

 access in the absence of the parent. Some birds desert their 

 nests on finding such unwelcome addition, while others hatch 

 and bring up the interloper. Usually only one, but some- 

 times even two, three or four Cowbirds eggs are found in the 

 nests of the smaller birds. 



The eggs are grayish white, thickly speckled with brown, 

 cinnamon, chocolate and allied colors, and measure about 

 0.90 X 0.70. The egg of the Cowbird hatches in ten days 

 while most of our smaller native species have an incubation 

 period of twelve to thirteen days or even longer, consequently 

 as the Cowbird is careful to lay her egg in nests in which the 

 eggs are fresh the young Cowbird hatches first and by the time 

 the rightful owner's young have hatched it is able to get a 



