12 BIRDS' NESTS 



artificial sites. By this means, we may incidentally 

 state, the iVIartin has been enabled to extend its 

 range into new districts, and has doubtless increased 

 accordingly. The Swallow at a similarly remote period 

 must have bred in caves and hollow trees, just as so 

 many kindred species do at the present time in wild 

 uncivilised countries. Like the Martin it haa not 

 failed to profit by the changed conditions afi'orded by 

 modern architecture, and nowadays attaches its nest 

 to rafters and other convenient ledges and projections 

 about houses, barns, and so forth. The Starling has 

 shown a very similar power of adaptiveness, whilst 

 the Jackdaw is perhaps quite as familiar and iftterest- 

 ing an instance. Lastly we may mention the House 

 Sparrow, a bird possessed of exceptional intelligence 

 and sagacity, and one which has not only changed its 

 nesting habits within historic time, but also its building 

 materials to an extent unequalled by any other known 

 bird. A still more extraordinary instance of changed 

 methods of nesting in this species in New Zealand (to 

 which country the bird has been introduced) has been 

 recorded in Nature (1888) by Mr G. L. Grant. He 

 writes as follows : " In many of the deep cuttings in 

 our roads, and on the cliffs upon our river banks, 

 where the formation is a light pumiceous sand, these 

 birds are in the habit of burrowing holes similar to 

 those of the Sand Martin. In some cases I have 

 found these burrows by measurement to be as much 

 as six feet in depth." Instances are also on record 



