18 On the M our ul -building Birds of Australia. 



it is often very small the first year, about 2 feet high and 



5 feet in diameter at the base^ and you find mounds from 

 that size up to 14 feet high and 35 feet in diameter at the 

 base. 



The birds generally make the top portion of the mound up 

 and add to it in July and August, apparently to let sufficient 

 moisture penetrate before they commence laying towards 

 the end of September or early in October, in a wet season 

 earlier, in a dry season later. The surface is scraped for a 

 considerable distance round the mound, holes often being 

 made from which they take the soil. 



The temperature of the part of the mound where the eggs 

 are placed is generally 95°, occasionally a little over, and a 

 clutch is nine eggs, that being the largest number I have 

 known to be taken out of one nest. So far as I can judge, 

 only one pair of birds use the same mound, and the male is 

 generally near at hand to repair any damage that may have 

 been done. When the hen bird is ready to lay she scrapes 

 a hole near the top of the mound to the depth of from 



6 inches to 5 feet, and the egg having been laid in the hole 

 she places it on end, with the small end downward, and 

 covers it up to the level of the rest of the mound. Occa- 

 sionally she makes an excavation straight in from the side, 

 but not often. The various holes are not placed in any 

 particular order, nor are they all of one depth. The egg 

 is laid at daybreak, and three days elapse between the laying 

 of each egg and the next. The egg being so large compared 

 with the size of the bird will quite account for the time 

 between the layings. The white shell of the egg is covered 

 with a pink substance, which easily flakes off when the egg 

 is dry. The eggs are about the same size and colour as those 

 of the Mallee-Fowl, so much so that the eggs of one bird 

 can easily be mistaken for those of the other. Incubation 

 takes about six weeks, and the young when hatched make 

 their own way out, as the parent birds, by frequently 

 scratching, prevent the soil from becoming caked and hard. 

 Only one egg is laid in each excavation, and the holes are 

 about a foot in diameter ; sometimes they go down straight 



