The Emu. 
17 
capturing its food, which consists of small reptiles and mice. 
The bird selects some point of advantage, and keeps a sharp 
look-out for its prey, pouncing down upon it with lightning-like 
rapidity. At other times it feeds in damp and swampy ground, 
collecting tor itself worms, grubs, slugs, and snails. 
But most harmless and yet most useful of all our insectivorous 
birds is the Ibis. There are three species, and the largest, the 
Straw-necked, can be taken as an example, not only of the Ibis 
family, but of all other inland plain wanderers, like the Bustard, 
the Curlew, the Plovers, and the Herons. The Ibis lives in 
flocks, numbering from 10 to 20 to many hundreds, and these 
systematically prospect great stretches of plain when feeding. 
The flock walks to and fro, turning over small stones for slugs 
and snails, and catching the wary grasshopper in myriads, for 
on these great plains the locust is at home, and if unchecked 
would rapidly increase. But while the Ibis remains nature's 
balance will be preserved. They are curious birds in that they 
do not breed every season, and only in a good year do they nest 
in any number. . The spring of 1900 was a good season, suitable 
in that there was the promise of an abundant food supply for 
themselves and their offspring. At one large swamp in Western 
Riverina two Field Naturalists came across a very large colony 
of birds nesting. The colony was made up of an immense 
number of flocks, which came from far and near, arriving at 
different times, for some of the companies were noticed with 
large young while others had just laid their clutch of 3 eggs. 
The birds were closely packed over 400 acres, and it was 
estimated that there were no less than 200,000 birds in the rookery. 
The crop of one adult bird examined contained actually 2,410 
young grasshoppers, besides several caterpillars and snails. 
And when it is remembered that each bird, besides having at 
least two meals a day itself, collects food for its offspring as well, 
then some idea can be formed of the myriads of locusts these 
birds demolish. The snails found in the Ibis crop were those 
that harbour the sheep liver fluke in one of its stages. 
Most helpful are the Cockatoos also. Although looked upon 
as a scourge to the farmer, yet they devour great numbers of 
grasshopper eggs, which they find in the ground. The female 
locust lays from 50 to 80 eggs in a small hole she has hollowed 
out for the purpose. The eggs are deposited in a compact mass, 
and these the Cockatoos root out with their strong bills and eat 
greedily. The Rose-breasted Cockatoo and the White Cockatoo, 
however, have bad reputations. They dig up newly-sown grain, 
and even after the crop has started will pull up the young 
plants for the sake of the grain, which still adheres to them. 
And, not content with this, they go through the field nipping 
off the young shoots as well. Then, again, in districts where 
maize is grown, the White Cockatoos destroy the seed cobs 
when they are ripening. The birds are extremely wary. They 
