CHINCHILLAS AND VISCACHAS. i 73 
Habitg The viscacha is by far the most common rodent on the Argentine 
pampas; and ail excellent account of its habits is given by Mr. W. 
H. Hudson, from which the following summary is compiled. These animals live 
in societies usually numbering from twenty to thirty individuals; they form 
warrens known as viscachera, each of which may contain from twelve to fifteen 
burrows, some of them being double or triple. Such a viscachera will cover 
from one to two hundred square feet of ground. The burrows vary much in 
extent; some opening out into wide chambers, from which other tunnels radiate; 
while others communicate with their neighbours. The whole viscachera forms a 
raised mound of earth which has been brought up from the burrows. It is always 
formed on the open plains; and the entrances to some of the compound burrows 
the viscacha 4 nat. size). 
are sometimes as much as a yard in diameter. Usually the burrow takes the form 
of the letter Y. A passerine bird ( Geositta ) belonging to the wood-liewer family, 
makes its breeding-holes in the sides of the viscacha-burrows; while when deserted 
by their rightful owners they are occupied by a kind of swallow ( Atticora ). 
Moreover, on the mound of the viscachera may frequently be observed a pair of 
burrowing owls (,Speotito ), which generally excavate a domicile for themselves, but 
sometimes occupy one of the burrows on the flanks of the mound. The whole of 
the ground in the neighbourhood of the burrows is carefully cleaned from all 
vegetation, the refuse of wdiich is heaped up near the entrance; and it is this 
habit which renders these animals so obnoxious to the farmer. Their usual food 
is grass and seeds, but they sometimes also eat roots; while in the dry season they 
are reduced to withered grass and thistles. When the herbage is green the 
viscachas require no water; but the first shower in the dry season brings them at 
once out of their holes to imbibe the much-needed fluid. 
