ERNEST WARREN. 



they are mostly confined in a capacious wired-in enclosure 

 protected from the rain, but quite frequently they escape 

 into the garden and climb among the trees. At the present 

 time there are five birds in the aviary ; namel}^, tAvo hybrids, 

 the parents of the same, and a second specimen of sulphur- 

 crested cockatoo. By wire-partitions and wire-cages the 

 birds can be separated from one another. This is particularly 

 necessary in the case of the elder of the hybrids, which at 

 times exhibits a violent disposition. The bird has already 

 killed a grey parrot, and has very severely mauled the second 

 specimen of cockatoo, which, nevertheless, is a considerably 

 larger and more powerful-looking bird. 



The female-bird was purchased some twelve years ago, and 

 the male-bird about four years afterwards. Thus the birds 

 have been associated together for a period of about eight 

 years. During the first two years the birds were not confined 

 at all ; they lived among the trees in a garden in a different 

 portion of the town. Apparently no pairing occvirred during 

 this period, and no eggs were laid. Subsequently the owner 

 moved to another residence and the birds were lodged in 

 their present quarters. 



It is difficult to say whether the closer association of the 

 two birds arising from the confinement favoured the pairing, 

 but for the following six years (1908-1913) eggs were laid 

 regularly every August. It is possible, however, that the 

 production of eggs by the female cockatoo does not necessarily 

 mean that copulation invariably took place; for in this connec- 

 tion it may be mentioned that a tame owl (Syrnium wood- 

 f ordi) in my possession occasionally produces perfectly formed 

 eggs, although the bird is unpaired ; also, a certain unpaired, 

 tame and unidentified parrot belonging to the Misses Black- 

 more of this town has laid eight or nine eggs annually for 

 several years. In the case of the birds with which we are 

 now concerned, actual pairing has been observed and probably 

 it occurred every season. 



The eggs are laid about the middle of August. In 1908 

 two «ggs Avere produced, and the owner, under the impression 



