AVIAN GENUS CHRYSOCOCCYX 85 



were "multiples" or "extra" eggs. That there may be some slight local 

 or individual variation in this matter ot miiltiple-egg laying is sug- 

 gested by the fact that of 12 nests with two didric eggs each, 4 were 

 found in central Natal (but over a period of seven years) — all in nests 

 of the Cape weaver, Ploceus capensis olivaceus. 



In the case of C. Haas the number of nest egg records is much 

 smaller, but it reveals that in each of 29 nests there was a single Haas 

 egg, and in 3 nests there were two such eggs apiece. Years ago H. L. 

 White (1915, p. 145) summarized his large number of records for three 

 Australian glossy cuckoos, basalis, lucidus (plagosus), and osculans, 

 and found that there was usually but one cuckoo egg in a nest. Occasion- 

 ally he found two lucidus or basalis eggs together and once even three 

 basalis eggs, but in these cases it is unknown if the multiple eggs were 

 laid by the same or by different hens. In the two Malaysian species 

 maculatus and xanthorhynchus , Baker's data included only single eggs 

 per nest, 11 in the case of rnaculatus, 9 for xanthorhynchus. 



In the instance White described where three basalis eggs were in 

 the same nest, they were actually buried at different levels in the nest 

 lining, so that this case was in effect, more comparable to three 

 separate nests than to one with multiple parasitism. Another instance 

 of three basalis eggs in a nest of Malurus cyaneus, reported by Parsons 

 (1918, p. 145), also involved eggs buried under later nest lining, but 

 in this instance it was not specified if they were buried together or at 

 dift"erent times. 



Interval between eggs 



The interval between eggs is stiff a matter of some uncertainty. There 

 is in the literature a tendency to assume that the small cuckoos, such 

 as Chrysococcyx, lay at daily intervals in contrast to the larger Cuculus 

 which lays at intervals of 48 hours. For example, in discussing the two 

 Asiatic species maculatus and xanthorhynchus, Baker (1942, p. 168) 

 wrote that two of his correspondents, C. M. Inglis and A. ^1. Primrose, 

 believed that these cuckoos laid at intervals of 24 hours, but added 

 that, inasmuch as he had never taken any but single eggs of these 

 birds, he could neither prove nor disprove the suggestion. Unfortunate- 

 ly, neither Inglis nor Primrose have recorded their observational data. 



In the case of the African caprius we have better, although con- 

 flicting information. In my earlier account (1949a, pp. 161-162) I 

 stated that the interval between eggs seems to be one day, not two as 

 in Cuculus, and pointed out that the pertinent evidence was of two 

 kinds. "In the ovaries of breeding females that I examined there was 

 less difference in the degree of collapse and disintegration of the dis- 

 charged follicles than in comparable material of Cuculus. This uiiplies 

 a shorter interval between successive discharge follicles, which leads 



