WESTERN AUSTRALIA 205 



These birds go south and meet the southern 

 species between the Gascoyne and Ashburton 

 Rivers. 



3. Inland from the whole of the coast of Western 

 Australia we meet dry country birds with a ten- 

 dency to be paler in plumage than the coastal birds. 

 In the ground loving birds the colour will be 

 according to the type of country upon which the 

 bird is living. This is where we find colour pro- 

 tection on a grand scale. 



4. The outland or island fauna is rather remark- 

 able. The Houtman Abrolhos e.g. are made up 

 of the most southerly coral islands in the Common- 

 wealth, and they are the meeting ground of myriads 

 of northern terns and southern petrels. Here they 

 nest in thousands, the first on the ground the sec- 

 ond below it in burrows. 



DESERT BARRIER IN OPERATION 



Birds of the north-west. 

 Birds of the south-west. 



Where there is a great desert there is no natural 

 facility to cross it. The tendency is to act as an 

 obstruction rather than to encourage travel or ex- 

 pansion. The migratory birds offer no objection, 

 as they journey miles above it, and close on a 

 thousand miles before alighting. 



With local birds of internal migration it is a 

 very serious matter when a dull broad stretch of 



