PARASITIC WEAVERBIRDS 47 



(1949, p. 663) found a nest containing two eggs of the cuckoo finch 

 and none of the host. Subsequently, at "Torre," near Marandellas, 

 Southern Rhodesia, Neuby-Varty (1950, p. 37) found a nest on Feb- 

 ruary 14, 1950, with one egg of the host and one of the parasite. In 

 the Selukwe Native Reserve, Southern Rhodesia, C. T. Fisher found 

 three more parasitized nests of this grass warbler (records of which 

 were not published but were sent to me by Harry M. Miles). The 

 first one was on March 19, 1954, a nest containing only a young cuckoo 

 finch with its feathers just sprouted. On March 27 it was well 

 feathered, and on April 4 it left the nest. On March 26, 1954, he 

 discovered a nest containing four eggs of the grass warbler and one 

 of the cuckoo finch, and on March 3, 1955, he found two fledgling 

 cuckoo finches that were still in or near the nest and were attended 

 by ^v^en grass warblers. The fledgling parasites were not yet able 

 to fly well. In 1954 and 1955, two further instances were reported to 

 to me. 



These actual cases are the only ones known to me, but a few other 

 incomplete and hence indefinite cases are also in my files. Chapin 

 (1954, pp. 407-410) listed the wren grass warbler as a known victim 

 of the cuckoo finch, probably on the basis of some of the above-men- 

 tioned records. J. Vincent (1936, pp. 102-103) noted numbers of 

 cuckoo finches near He, Mozambique, in fields where the wren grass 

 warbler was present. 



Wren grass warblers are very prone to desert their nest if they are 

 touched by the observers, and Neuby-Varty suggested that this same 

 tendency may also pertain to nests intruded into by the cuckoo 

 finches. As a consequence, a considerable percent of eggs of the 

 latter would be lost. 



Desert grass warbler: Cisticola aridula Witherby ^^ 



Neuby-Varty (in litt., June 24, 1956) wrote me that on February 9, 

 1956, on his ranch "Torre" near Marandellas, Southern Rhodesia, 

 he found a nest of this species with two of its own eggs and one of the 

 cuckoo finch — aU about half incubated. The race of the host involved 

 was C. a. kalahari Ogilvie-Grant.^ 



Brown-grass warbler: Cisticola brunnescens Henglin ** 



In northwestern Ethiopia, Cheesman (in Cheesman and Sclater, 

 1935, p. 615; 1936, p. 194) found the nominate race of the brown grass 

 warbler to be parasitized by the cuckoo finch (which he erroneously 

 listed as the pin-tailed wadow bird, Vidua macroura, but later cor- 



»» Cisticola aridula Witherby, Bull. British Omith. Club, vol. 11, 1800, p. 13 (60 miles south of Khartoum, 

 i.e., Gerazi, ^^*hite Nile). 



" Cisticola kalahari Ogilvle-Grant, Bull. British Omlth. Club, vol. 25, 1910, p. 121 (Molopo River, 

 Bechuanaland). 



M Cisticola brunnescens Heuglln, Joum. Omlth., vol. 10, 1862, p. 289 (Qudofelasl, Scrawl, Abyssinia, 6,000 

 feet). 



