THE BIRDS OF AUSTRALIA. 
in extent and intensity as the range of the species extends farther north. Some 
trace of barring can be detected on the flanks in all the skins. In South Australia 
the stomachs of this Cuckoo usually contained remains of the hairy procession 
caterpillar. I have seen the birds picking out the caterpillars from the large 
silken nest this caterpillar congregate's in. The hair of the caterpillar is apt 
to cause a rash on the skin of people handling it, but the Cuckoo appears to 
find no ill effects.” 
Mr. A. G. Campbell wrote me : “ This Cuckoo is very common in ‘ Big 
Scrub,’ Richmond River, New South Wales, and in the Dandenong Ranges, 
Victoria. I have seen a fledghng of this species in a nest of Petroica rodinogaster. 
Upper Yarra, Christmas, 1904, at that time a new record as a foster-parent. In a 
restricted mountain gully of the Dandenong Ranges, in 1895, I discovered nine 
nests of Petroica rosea in one day, most of them containing fledglings. Visiting 
the locality several times in 1901 I was able to take three eggs of this Cuckoo, 
all from Robins’ nests, and I also discovered two young Cuckoos being fed by 
their foster-parents. During 1906, though I may not have searched as carefuUy 
as hitherto, I did not find a single Rose-breasted Robin’s nest, nor see a single 
bird. I do not blame egg-collectors for this, but I accuse the Fan-tailed 
Cuckoos of practically exterminating a lovely species of Robin in a lovely spot 
(part of a National Park, in fact), where it ought to be safe from extinction by 
artificial agents. Egg-taking does not decimate numbers ; it has rather the 
reverse effect, it is an incentive to greater fecundity, as instanced in the barn- 
yard fowl. But the methods of the Cuckoo are more than a match for any 
other species it insinuates itself upon. The Cuckoo’s numbers are, it seems, 
increasing annually in proportion to those of its foster-parents, for every 
Cuckoo reared means two, perhaps three, less host birds.” 
This same item was drawn attention to in connection with the European 
Cuckoo and the Reed- Warbler, where it was suggested that the Cuckoo preyed 
upon the host until it became a minimum, when it transferred its parasitical 
habits to another host until the Reed- Warbler had recovered, by normal breedings, 
its numbers sufficient to act as host, and probably the host preyed upon in 
the meanwhile had become incapable of attending to the numbers of the Cuckoo. 
This seems a matter worthy of more attention than has yet been given to it, 
especially in conjunction with different localities and years. 
Captain S. A. White has written me : “ The Fan,-tailed Cuckoo in some 
instances remains with us upon the plains all the year. Its weird note is 
heard in June sometimes, but generally in July and August, after which it 
ceases calling ; as soon as it moves on the wing the smaller birds ‘ mob it.’ 
I look upon this as a coastal bird, for I have never met with it in the far north, 
but plentiful up to sixty or eighty miles from the coast.” 
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