CHOPI 133 
never seen it, except as a cage-bird; nor is there 
anything about it in the notes of recent collectors 
and travellers who have visited the upper waters of 
the Plata. This however is not greatly to be regretted, 
since Azara gave a full and spirited account of this 
species in his Birds of Paraguay, although it does 
seem strange that the Chopi should have had two 
careful observers of its habits over a century ago, 
namely Azara and his friend and fellow naturalist, 
the priest Noseda, and not one since. It is to give 
my English readers a specimen of Azara’s writing 
that I have introduced the Chopi, the only bird 
described in this book which was not known to me 
from my own observation. 
Evidently Azara was very familiar with it, for he 
described 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 verandas 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 Chop1 
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 than it is again subjected to fresh insult. 
These attacks on so large and powerful a species 
