A NEST OF IRON-STONE 



are usually found in dense thickets near the seashore, or on 

 the shore itself, and are often covered with vegetation, such 

 as the large yellow-blossomed hibiscus. Those upon the 

 shore are generally formed of sand and shells, without a 

 vestige of any other material. Occasionally they may contain 

 a little soil and decaying wood, but unlike the mallee- 

 birds 1 nests, there is nothing in the nature of a hot-bed, 

 and it is clear that for their incubation the megapodes' 

 eggs are dependent upon the heat of the sun. These sandy 

 mounds are often very irregular in shape, and might almost 

 be mistaken for banks thrown up by a heavy sea. One in 

 Knocker's Bay was upwards of twenty-five feet long and five 

 feet high ; another measured a hundred and fifty feet in cir- 

 cumference, and was made of pebbly iron-stone a strange 

 material for a nest ! As a rule, however, the bird displays 

 a more gentle instinct towards its eggs, for those mounds 

 which are made in the thickets consist of a light, black vege- 

 table soil. It is a remarkable fact that in barren districts 

 megapodes 1 mounds are sometimes found composed of this 

 same black mould, although there may be no earth like it for 

 miles around, and it has been supposed that the birds fetch it 

 from afar. We have seen, however, how little they seem to 

 care about providing a soft bed for their eggs, being quite 

 content to make use of whatever material they happen to find 

 on the spot, so that it is far more probable that they gather 

 together a few dead leaves and that the black soil is formed 

 by their decomposition. These earthy mounds are not irre- 

 gular in shape like the heaped-up masses of sand and shells 

 upon the shore, but more or less definitely conical. The 

 eggs are placed in holes which are dug from the top to a 

 depth of six feet or so and generally (but not always) slope 

 outwards to within two feet of the side of the mound. The 

 natives informed Gilbert that the birds lay only one egg in 



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