THE PASSING 67 



A good observer states that in the dry north-east 

 of Victoria little Red-cap, who is often known as 

 the Mallee Robin, breeds in August and December; 

 but the only months in which I found nests further 

 south were October and November. It is a curious 

 fact that few other nests are so cosily lined as this 

 curious because it would seem that a plentitude 

 of feathers and other soft material would be more 

 suitable to an early-nester such as the Yellow- 

 breasted Robin. Reflecting on this point the nega- 

 tive value of blankets in warm climates I have 

 sometimes wondered whether little Red-cap has 

 evolved the practice in question for the confusion 

 of interloping Cuckoos, a casual theory which gains 

 some little strength from the finding of an egg 

 tucked away under a mass of feathers after the 

 single baby bird had left the nest. If the Robin's 

 own egg may be hidden in this way, may not the 

 intruding egg of a Cuckoo be similarly treated? 

 Indeed, may not the thick lining act as a screen 

 from the Cuckoo itself, which, it seems, has a 

 thoughtful habit of removing an egg before adding 

 its own product to a clutch? 



It is all very big and very wonderful, this prob- 

 lem constituted by a family of birds which have so 

 far forgotten a fundamental principle of life as to 

 foist their offspring upon other birds. And not the 

 least remarkable point in the puzzle is the attitude 

 of the foster-parents. When this role is merely 

 prospective they will repulse the Cuckoos with all 

 the fierceness and clamor of outraged respectability ; 

 but once the egg is deposited, be it ever so unlike 



