Some Foreign Bird Architects. 



to the seashore, or on the shore itself, those built in 

 the latter situation being often very irregular in shape, 

 and generally formed of sand and shells. Some of these 

 shore mounds have been found to measure as much 

 as a hundred and fifty feet in circumference ; while the 

 mounds built in the thickets are more regular in shape, 

 and generally composed of a light black vegetable soil. 

 The parent birds dig down into these mounds from 

 the top, excavating holes in which the eggs are placed, 

 their incubation being accomplished by the heat of the 

 sun's rays pouring down upon the mound and raising 

 the temperature within. 



Gould has left the following particulars concern- 

 ing the mounds made by these remarkable birds ; and 

 his remarks and observations are of particular value, 

 as these birds are almost certain to grow rarer as the 

 country becomes opened up and more populated. " I 

 revisited Knocker's Bay," writes Gould, " and having 

 with some difficulty penetrated into a dense thicket 

 of cane-like creeping plants, I suddenly found myself 

 beside a mound of gigantic proportions. It was fifteen 

 feet in height and sixty in circumference at the base, 

 the upper part being about a third less, and was en- 

 tirely composed of the richest description of light vege- 

 able mould ; on the top were very recent marks of 

 birds' feet. The native and myself immediately set 

 to work, and after an hour's extreme labour, rendered 

 the more fatiguing from the excessive heat and the 

 tormenting attacks of myriads of mosquitoes and sand- 

 flies, I succeeded in obtaining an egg from a depth of 

 about five feet. It was in a perpendicular ^position, 

 with the earth surrounding and very lightly touching 



217 



