VALUE OF BIRDS TO MAN BUCKLAND. 445 



form the function of a native species that has been driven out, and 

 where that function has been performed satisfactorily. But, as a 

 rule, such substitutions are fraught with danger. Birds so rapidly 

 change their habits in new surroundings that few species remain 

 loyal to the reputation for honesty which they enjoyed in the land of 

 their origin. Like most aliens, it would have been better had they 

 remained in their own country. Although the spread of civilization 

 unconsciously demands some victims, man and indigenous birds can, 

 speaking generally, occupy the same territory without much diffi- 

 culty. If one requires proof of this, he has but to turn his thoughts 

 to British India, where native birds of all kinds, owing to the protec- 

 tion accorded them by the Hindu doctrine of the sanctity of all life, 

 are found living in closest proximity to dense human populations. 



The moral of all of which is that it behooves every man who has 

 the welfare of his country at heart to do all in his power to foster 

 native birds. 



In Australia a plague of gi-asshoppers periodically visits the fields 

 to devour the crops. The ruin they would otherwise bring on the 

 farmer is averted by the good offices of ibises and other native birds. 

 As a destroyer of grasshoppers, the straw-necked ibis {Carphihis 

 spinicoUis) has no equal among birds. Dudley Le Souef, the director 

 of the Melbourne Zoological Gardens, some years ago visited a rook- 

 ery of this bird in the Riverina, and, after a careful estimate, came 

 to the conclusion that the minimum number of birds breeding there 

 was 200,000. He procured a number of specimens and ascertained 

 by actual counting that the contents of an average crop of an adult 

 bird were 2,410 young grasshoppers, 5 fresh-water snails, and several 

 caterpillars, which, multiplied by 200,000, amounts to a total of 

 four hundred and eighty-two million and odd grasshoppers, as well 

 as vast numbers of caterpillars and snails. " Then, again," says Mr. 

 Le Souef, " the average number of young is about two and one-half 

 to each pair of parent birds, and the contents of their stomachs must 

 reach an enormous total, as they all seemed gorged with food." 



As this enormous amount of food is being eaten every day by 

 ibises in Australia during the hatching time of the grasshoppers, 

 some little idea can be formed of the immense utilitj- these birds are 

 to the farmer. Without them the balance of nature would be dis- 

 turbed and successful agriculture would be impossible. 



In addition to its great value as a destroyer of all-devouring in- 

 sects, the straw-necked ibis feeds with avidity on the fresh-water 

 snail — ^the host of the dreaded liver fluke, which sheep so easily get 

 in certain damp localities. 



Yet, in face of these facts, people surreptitiously visit the breeding 

 gi'ounds of these birds and collect their eggs by the cartload. One 

 party in 1912, having gathered more than it required, drove away 

 and left 4,800 eggs to rot on the ground. 



