14 SOME USEFUL AUSTRALIAN BIRDS. 



similar migration of the Black-tailed Native-hen into South Australia in 

 1840, when these birds appeared in numbers in the streets of Adelaide. 

 Gould quotes similar observations in the introduction to the "Birds of 

 Australia." Tn 1906, on the swampy land of the Darling and Barwon 

 rivers, I saw these birds covering acres of land. These and other birds come 

 and go; but we have other experiences where strange birds extend their 

 range southward or coastward from the interior, and finding the new location 

 suitable, either take up their abode there, or else return regularly each 

 season to nest. South of the Murray, in the Gunbower district, no pelicans 

 were known when selectors began to occupy the lands in 1875, but five years 

 later, large numbers appeared on the Kow Swamp. They are now to be found 

 all over the larger swamps and lakes, fishing in all the creeks and lagoons. 



Effect of Changinj Environment on the Habits of Birds. 



In going into the matter of wild life protection we will find that there 

 are many unnoticed influences which affect the distinctive fauna of any new 

 country like Australia. There is not the least doubt that with the advance 

 of civilisation, when cities spring up, the foi'est disappears ; and where the 

 farmer ploughs the land the natural herbage vanishes, and so thousands of 

 little creatures, from insects to birds and animals die out or move on as their 

 food supply fails. It is not only the gun of the hunter that kills. If you 

 destroy the natural food of any bird or animal, it may, if of an adaptable 

 nature, find some of the crops grown by the farmer or gardener just as suit- 

 able for food as the original supply ; and so a creature which was under 

 natural conditions, if not useful, at least harmless, becomes a pest. 



The same state of things comes about when, through the destruction of a 

 natural check upon its undue increase, a useful insectivorous bird increases 

 more rapidly than under the original conditions of life, so that the food supply 

 is insufficient. The farmers' crops are then affected, perhaps not sufficiently to 

 wholly counterbalance the good the birds do in the destruction of pestiferous 

 insects, but to such an extent that the practical farmer takes steps to destroy 

 with poison or gun, a bird he once looked upon with a friendly eye. On the 

 northern plains of Victoria I once watched this evolution of useful to in- 

 ju)-ious birds take place in the course of a very few years. When I first went 

 on the land it was subdivided into very large paddocks, in which the squat- 

 ter grazed sheep. Then came the selectors under the new Land Acts ; the 

 station holdings were cut up into small blocks, and fenced into smaller hold- 

 ings of 320 acres, or even less. U nder the old regime bird and animal life had 

 not altered much from earlier normal conditions, under which it is quite safe 

 to say that from 25 to 50 per cent, of the eggs and nestlings of the magpies. 

 Magpie-larks, and numbers of other insectivorous birds fell victims to hawks, 

 crows, Whistling-jackasses and to our innocent-looking friend the Laughing- 

 jackass. With settlement came sheep-worrying dogs, and the squatter and 

 selector laid poisoned baits or poisoned the body of a sheep that had been 



