The Cow-birds 319 



Hudson says that the same curiosity was exercised by the 

 Cow-birds towards any nesting boxes he put up for the 

 accommodation of birds in his homestead, and although 

 they exhibited the Hveliest curiosity, they never seemed 

 to be able to face the darkness of the interior, and never 

 deposited any eggs. 



Mr. Hudson says that he believes that every female of 

 the above-mentioned species laj^s from sixty to a hundred 

 eggs every season, though he admits that he has no actual 

 proof of this, beyond the evidence of the extraordinary 

 number of wasted eggs which are found. He also calls 

 attention to the mistakes and apparent imperfections in the 

 bird's economy, as follows — (i) The Cow-birds frequently 

 waste their eggs by dropping them on the ground. (2) The)' 

 also frequently lay in old forsaken nests. To make sure 

 of this fact, he has placed several old nests in trees and 

 bushes and found that eggs were laid in them. (3) They 

 also frequently lay in nests where incubation has actually 

 begun. When this happens, the Cow-bird's egg is lost if 

 incubation is far advanced. (4) The female often lays 

 several eggs in the same nest, instead of laying only one, as 

 the North American species of Cow-bird do. (5) Several 

 females lay in one nest, so that the number of eggs in it 

 makes incubation impossible. One December, Mr. Hudson 

 collected ten nests of the Scissor-tailed Tj'rant-bird 

 {Milvidus tyranniis). They contained a total of fort}'- 

 seven eggs, twelve of the Scissor-tails and thirty-five of the 

 Cow-birds. Probably three-fourths of the nests of the 

 Scissor-tails are abandoned in consequence of the confusion 

 caused in them by the Cow-birds. (6) Both male and 

 female Cow-birds destroy many of the eggs in the nests 

 they visit, by pecking holes in the shell, breaking, devouring, 

 and stealing them. To such an extent do the birds carry 

 this destructive habit, that Mr. Hudson has often carefully 

 examined all the parasitical eggs in a nest, and after three 



