204 Dove, No/es on Parasitism. [,sf M.rii 



known, by White's own observation, to incubate its eggs, 

 Herissant's contention that he had discovered the cause of para- 

 sitism fell to the ground. 



Curiously enough, the same idea has been advanced in this 

 •present year (1919) — considerably over a century after White's 

 time. Some discussion on the food of Cuckoos, especially the large 

 hairy caterpillars which are said to be tackled only by the 

 CnculidcB, has been going on in the Daily Chronicle, a London 

 journal, and a lady naturalist. Miss K. J. Edmonds, says that 

 "to fit him for his allotted task the Cuckoo is mainly stomach, 

 that portion of his anatomy being extra large and thick, to enable 

 him to digest his hairy food. Incidentally, the size and thickness 

 of the stomach and its walls make it physically impossible for the 

 lady Cuckoo to sit on her eggs, so if Cuckoos are to be hatched it 

 must be done by other birds. The mother Cuckoo has to work 

 hard to find a home for her eggs, and loses far more than she can 

 find homes for in time." Thus far Miss Edmonds. Personally, 

 I do not give any credit to this theory, for the reason that our 

 Australian species also feed largely on hairy caterpillars, and at 

 the same time are able to sit so comfortably on stumps or fence- 

 posts that I cannot believe they could not be equally comfortable 

 on a nest. The most casual observer must have noticed how 

 closely the Pallid Cuckoo (C. pallidus) and the Fan-tailed Cuckoo 

 {Cacomantis flabelliformis) squat down on such perches as 

 mentioned above, until their legs are completely concealed by the 

 plumage — in fact, from their appearance when thus " taking 

 things easy " one would imagine they would make admirable 

 mothers. 



The cause of parasitism is much more deeply seated, and lies, 

 in my opinion, on the same plane as the " polyandry " which is 

 always mingled with it. I believe that all the Cuckoo species (4) 

 which visit Tasmania are polyandrous, and they are all parasitic. 

 The only Australian species which is non-parasitic is the Coucal 

 {Centropus phasianus), and that is not polyandrous, but pairs 

 in the ordinary way, so far as has been observed. If internal 

 peculiarities prevent the members of the Cuckoo family from 

 undertaking the duties of incubation, how is it that the American 

 species, the Yellow-billed {Coccyzus americamis), and its congener, 

 the Black-billed {Coccyzus dominicus), both" build nests and rear 

 their own young, except on rare occasions, and both take heavy 

 toll of the large hairy larvre which are said to require cum]:)rous, 

 thick-walled stomachs ? 



The birds which are consistentl}' parasitic on the American 

 continent belong to quite another family — the Icteridce — and the 

 common North American species, the Cow-Bird [Molathrus ater), 

 much resembles the European Starling {Sturnus vulgaris) in 

 general appearance. In that interesting volume, " The Bird 

 Book," Eckstorm, quoting Major Bendire's " Life-Histories of 

 North American Birds," says that " a curious fact about the 

 Cow-Birds is that the males so outiiumhey the females that there are 



