134 BIRDS OF LA PLATA 



may be regarded as mere impertinences, but by 

 practising them the Chopi is soon able to rid himself 

 of the presence of any unwelcome bird* From a 

 long distance he recognises an enemy, by its figure 

 or even its shadow, and warns all birds of the coming 

 danger with a loud whistle, which at once sends 

 them into hiding, while the Chopi goes bravely out 

 to the encounter ; and the result is invariably a 

 victorious song on his part, beginning with the sound 

 of his own name, and running through a variety of 

 whistled notes* He also sings well in captivity and 

 when his mate is incubating ; and his voice is first 

 heard welcoming the dawn from the eaves and tiled 

 roofs of houses where he roosts* The pairing-season 

 is in November ; and, Noseda adds, the breeding- 

 place is a hole in a bank or tree-trunk, or in a wall 

 under the eaves, and occasionally the nest is made 

 in the small branches of an orange or other close- 

 leafed tree, and is built of sticks and straws carelessly 

 disposed, with a few feathers for lining* The eggs 

 are four, and white. 



It may be added that between Azara and his friend 

 Noseda there was a great controversy respecting 

 the parasitical habits of the Common Cow-bird 

 (Molothrus), which were first discovered by the 

 former and disbelieved in by Noseda, who accounted 

 for the fact that the Cow-bird is never seen to make 

 a nest by supposing that species to be the year-old 

 young of the Chopi, which, he further imagined, 

 took three years to acquire the adult form and 

 plumage. Such an idea might seem to discredit 



