AFRICAN PARASITIC CUCKOOS — FRIEDMANN 385 



begun laying. In at least one instance where the cuckoo laid in a 

 nest already containing eggs of the host, it did remove one of them 

 when depositing its own. 



Incubation Period 



The nest of a Cape robin-chat studied by Liversidge, mentioned 

 above, yields the following information on this topic. The person 

 who first showed him the nest was quite definite that the eggs (one 

 each of the cuckoo and the host) were first present on September 21 

 (about a week before Liversidge first saw the nest). The cuckoo's egg 

 hatched on October 7, which implies that at least 16 days elapsed 

 between the time the egg was laid and the date of hatching. It is not 

 known, however, if the host began to incubate on or immediately 

 after September 21; but at least it is clear that no eggs were laid in 

 the nest subsequent to the two seen on September 21, and it would 

 seem that incubation may well have started on or just after the date 

 of laying. This account leaves much to be desired, but it suggests an 

 incubation period somewhat longer than the one of 12}^ days reported 

 for the related European cuckoo, Cuculus canorus. More accurate 

 data are needed to clarify this point. 



Host Records 



Accumulation of many additional host records indicates even more 

 strongly than before that the robin-chat Cossypha cafra is the chief 

 victim of the red-chested cuckoo wherever the two occur together. 

 At least three subspecies of the Cossypha are now knovfn to be para- 

 sitized: the nominate one, for which I had numerous records previously 

 and for which I could add at least as many new ones now; the tropical 

 race iolaema, earlier listed on the basis of a single instance to which 

 several more may now be added (Wiley, 1948, p. 2) ; and the subspecies 

 drakensbergi, recently found to be victimized at Underberg, Natal, 

 by Tait (1952, p. 135). 



The Natal robin-chat was previously listed as a host of the red- 

 chested cuckoo solely on the strength of Roberts (1939, p. 8), who lists 

 it in this capacity. No specific records or other data were given by 

 him. Recently Mr. H. M. Miles has informed me that at Melsetter, 

 Southern Rhodesia, a correspondent of his saw a fledgling of this cuckoo 

 attended by a Natal robin-chat. There is nothing unexpected about 

 this record, but it is a welcome additional indication to the not too 

 informative statement given by Roberts. 



One species has been added to the list of known hosts by Haydock 

 (1950, pp. 149-150) at Luanshya, Northern Rhodesia. This is 

 another species of robin-chat, Cossypha heuglini, in a nest of which he 

 found, on October 22, two eggs of the owner. An hour later a red- 



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