MOUNDS RAISED BY BIRDS. 245 



method of proceeding, and actually resorting to 

 the employment of artificial heat in the process. 



The wattled talegalla, a bird which is found in 

 various parts of New South Wales, but which is 

 being rapidly extirpated by the assaults of the 

 cedar-cutters, and other sportsmen, is one of 

 those singular birds who adopt what we may pro- 

 perly call artificial incubation for their eggs. Mr. 

 Gould informs us, that it is in the habit of collect- 

 ing an immense heap of decayed vegetable matter 

 as a depository for its eggs, trusting to the heat 

 developed during the process of decomposition for 

 the perfecting of the incubation of its eggs. The 

 heap employed for this purpose is collected by the 

 birds during several weeks previous to the period 

 of laying. It varies in size, from two to four 

 cart-loads, and is of a perfectly pyramidal form. 

 The construction of the mound is not the work of 

 one pair of birds, but is effected by the united 

 labours of several. The same site appears, from 

 the great size and the entire decomposition of the 

 lower part, to be resorted to for several years in 

 succession, the birds adding a fresh supply of 

 materials on each occasion previous to laying. 

 The mode in which these mounds are raised is 



