BIRDS OF OUR BUSH 



found on top of the eg-g-chamber. For the benefit of 

 those who do not already know the nest, it may be as well 

 to describe it, as we are unable to reproduce a photograph 

 of it. The nest proper is a roughly spherical structure, 

 entirely closed in except for a small entrance in the side. 

 This portion is warmly lined with feathers and the like, 

 quite calculated to provide shelter and warmth during the 

 rough weather which it usually encounters. The pecu- 

 liarity of the nest lies in the fact that on the top of the 

 egg-chamber will usually be found a shallow open shelter 

 not unlike the cup-shaped nest built by such a number of 

 birds. The occurrence of this open shelter is no accident 

 either, as is proved by the fact that where circumstances 

 have prevented its being built on top of the egg-chamber, 

 we have found it to be placed separately a few inches from 

 the main structure. 



What particular purpose this second nest serves is diffi- 

 cult to determine. One explanation ofi'ered is that the 

 Tom-tit hopes by its presence to induce the Cuckoo to place 

 there its unwelcome egg instead of in the nest proper. We 

 find ourselves unable to incline to this view, as we have 

 never yet come across a case where this object had been 

 accomplished, and, furthermore, have heard of few being 

 recorded. It is unlikely that the bird would persist in the 

 erection of a structure which experience proved to be use- 

 less. Our idea, certainly not backed by any definite proof, 

 is that the second nest is used by the non-sitting bird as a 

 shelter during the night. It has the appearance of being 

 tenanted, and does not become dilapidated as would appear 

 inevitable if it were not in use and kept in repair. There 

 is one other possible explanation which occurs to us as a 

 result of some experience of cage birds. Certain well- 

 known Australian Grass Finches we have noticed to con- 

 struct a small open shelter when their young are advancing 

 towards the flying stage. The young Finches, when they 

 leave the nest, are nightly enticed by the careful parents 

 into this shelter. Possibly the structure built by the Tom- 

 tit is intended for a similar purpose. 



The Tom-tit is an early builder. Nearly always it is 

 the first nest we find, and may be looked for about the 

 middle of the month of June. Nests as late as Christ- 

 mas time are by no means uncommon either, but July, 

 August, and September are the principal breeding months. 



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