AVIAN GENUS CHRYSOCOCCYX 45 



checklist committee are still undecided about many of them. In the 

 following list the known hosts are merely listed b}^ species in the order 

 of the 1926 Australian checklist, but with their nomenclature brought 

 up to date.* 



If one considers the large amount of raw data summarized in this 

 mere list, it is unfortunate to have to say that it does not convey a 

 very realistic picture in some important respects. Thus, while I have 

 had much kind cooperation from numerous Australian correspondents, 

 the records here amassed are frequently without detailed information, 

 and, as might be expected, it is often difficult to assess the frequency 

 with which certain species are parasitized. Unusual host records are 

 more apt to be reported than are repetitive ones of the frequent 

 hosts, and it is the latter that are really important in the biology of the 

 cuckoo. All in all, I have been able to compile some 386 records for 

 these 100 hosts, and of these 100 fosterers 26 are included on the basis 

 of only a single record apiece, 31 on the basis of two instances each, 16 

 on the basis of three records, 7 on the basis of four, and 20 are species 

 for which there are five or more known instances of parasitism. 



The fairy wrens of the genus Malurus, the thornbills, Acanthiza, 

 and the robins, Petroica, are the most frequently used victims. Ten 

 species of Malurus account for 109 records, or 28 percent of the total, 

 and of these the blue wren, M. cyaneus, leads with 62 records, or 16 

 percent of the total, with the black-and-white wren, M. leuconotus 

 second with 15 records. These figures are probably far too low, as only 

 a smaller percentage of records of commonly used hosts are published, 

 as compared to the fact that almost all unusual ones do find their way 

 into print eventually. Thus, in a recent letter Lindsay Hyem wrote 

 that in his area, near Barrington, New South Wales, basalis is very 

 selective, probably 90 percent of their eggs being laid in nests of the 

 blue wren. His statement is by no means unique, but he thought that 



^ For pertinent published references see: Barnard 1915, p. 43; Barnard and 

 Barnard 1925, p. 260; Campbell 1898b, pp. 151-154; 1902, p. 12; 1906, p. 197; 

 1913, p. 71; 1927, pp. 300-301; Carter 1903, p. 89; Cayley 1950, p. 70; Chenery 

 1924, p. 224; Chisholm 1920, pp. 315-316; Cleland 1924, p. 181; Cohn 1924, p. 76; 

 de Warren 1926, p. 78; Dickison 1928, p. 151; Dove 1924, p. 156; 1928, p. 224; 

 Gilbert 1935, p. 22; Givens 1925, p. 28; Hill 1907, p. 21; Hill 1903, p. 165; Hobbs 



1961, p. 42; Howe 1910, p. 163; 1913, p. 190; 1928a, p. 216; Kikkawa and Dwyer 



1962, p. 169; Leach 1928, p. 91; 1929, pp. 180-181; Littlejohns 1943, pp. 250-251; 

 Littler 1910, p. 85; Macgillivray 1914, p. 163; 1924, p. 15; Mc Gilp 1921, p. 240; 

 1923, p. 279; 1925, p. 5; 1926, p. 278; 1935, p. 12; Mellor 1917, p. 18; North 1893, 

 p. 373; 1894, p. 327; 1895, p. 39; 1897, p. 26; 1912, p. 26; Orton and Sandland 

 1913, p. 78; Parsons 1918, p. 145; Ross 1913, pp. 280-281; 1919, p. 303; 1926, 

 p. 137; Rowley 1965, pp. 274-275; Sandland 1909, p. 150; Schnowetter 1964, p. 

 569; Serventy 1929, p. 192; Serventy and Whitell 1948, p. 237; 1962, p. 268; 

 Smith 1926, p. 296; White 1910, p. 49; 1915, pp. 150-152; Whitlock 1910, p. 193; 

 Wilson 1914, p. 170; 1918, p. 235. 



