212 AUSTRALIAN BIRD MAPS 



which may vary in quantity and quality of insect 

 life and seeds, just as thousands of water birds do, 

 when their swamps dry out (Tribonyx). 



The Crow and the Pipit are well distributed, the 

 the former being local in large areas extending to a 

 third of the continent. The latter is constant to 

 limited areas e.g. the height and depth of a moun- 

 tain, or a plain between two mountain ranges, or 

 small portions of an indefinitely unbounded plain. 

 Several species are local in the southern summer, 

 and local in the north in winter (Chats). 



The Magpie-Lark and Scrub-Wrens are local 

 throughout the year. There are thirty species of 

 purely Australian birds commonly found over 

 Western Australia and all over Australia. To 

 these might be added approximately another thirty 

 species which come in from Asia, to spend the six 

 summer months in Australia. 



IRREGULAR ORIGIN 



There is a bird in the far north-west living away 

 from most other birds, by name the Carter Desert 

 Bird (Eremiornis carteri). If it has company we 

 may conclude it is the Bush Lark (Mirafra). Both 

 these birds have an African origin, via India, but 

 they do not seem to have immigrated into Western 

 Australia by way of Northern Queensland. The 

 Desert Bird is found only in N.W.A. though I sus- 

 pect it was once in the west of the Northern Terri- 

 tory coming across direct from Timor. The Bush 



