SOUTH AND CENTRAL AUSTRALIA 179 



mintina River. The Rainbow Bee-eater does the 

 same. 



This appears to be the main line of migration 

 for South Australian birds, map 75, a second line 

 being along the Murray and Darling basins. 



KEY TO THE DISTRIBUTION OF RACES 



Our interest is invited to map 76 and its text. 

 A robin is given as an example of a bird showing 

 geographic differences according to the type of 

 country in which it is living. It fairly well par- 

 titions South Australia into climatic and vegetarian 

 differences. Flinders Range, the northern end of 

 the South Australian highlands, has its direction 

 north and south. As it passes northward there is 

 a tendency for the birds to yield their coastal char- 

 acters in favour of those of Central Australian 

 birds. This is particularly so at the north end 

 where the range passes through plains into the 

 interior. The pittosporum and quondong (Fus- 

 anus) yield tender berries to berry-eating species, 

 the acacias provide tough seeds for the strong bills 

 of the Cockatoos. Native fuchsia bushes (Eremo- 

 phila) attract the Pied Honey-eaters. Callitris, the 

 native pine, shelters many birds. 



Passing over porcupine bush the great interior 

 is entered. The waterless mulga scrub and soft 

 sand harbour the one common species, Thick-billed 

 Thornbill ; a bird living on insects for food and 



drink. In the dry grassed sandy open tracts an 

 12 



