APHOBUS CHOPI. 109 



priest Noseda, and not one since. Evidently Azara was very familiar 

 with this bird, for he describes it lovingly and at great length, his 

 history of it being one of the most charming things in his work. 

 According to him the Chopi is a highly sagacious bird, and although a 

 frequent visitor to courtyards and verandahs of houses in Paraguay, too 

 shy and suspicious to be caught with snares. It has a strong and easy 

 flight, and readily attacks any large bird passing near, following it 

 persistently in the air, or, pouncing down, fastens itself on its enemy's 

 back. If the Caracara Eagle (Polyborus) alights in order to shake off 

 its persecutor, the Chopi perches at a distance of a few feet, where it 

 assumes an indifferent manner; but no sooner does the Caracara allow 

 its attention to wander from its adversary, then it is again subjected to 

 fresh insult. These attacks on so large and powerful a species 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 recognizes 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-trunks, 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 (Molothrtui) , 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 Noseda as a naturalist, if we did not remember that Gilbert 

 White at the same period was trying to prove the hybernation of 

 Swallows in England. The whole of the discussion appears in the 

 ' Apuntamientos/ under the description of the Chopi ; and Noseda is 

 there allowed to state his own case ; after which the better observer, 

 Azara, gives five objections to the theory, any one of which would be 

 sufficient to demolish it. 



