NO. 4 AVIAN GENUS CLAMATOR — FRIEDMANN 21 



nonexistent its absence seems quite unimportant. Baker's data ( 1942, 

 p. 83) on this cuckoo in India reveal a strong correlation between 

 percentage of host acceptance of its eggs and the degree of egg 

 resemblance involved, and, conversely, between the incidence of re- 

 jection when the cuckoos' eggs are deposited in nests of nonadaptive 

 hosts and the degree of difference in the eggs of the two. Thus, of 

 106 parasitized nests of "normal" {i.e., egg-adapted) fosterers, only 

 1 was deserted (less than 1 percent) ; of 48 parasitized nests of "un- 

 usual" fosterers, 3, or 6.25 percent were deserted; of 8 parasitized 

 nests of "abnormal" fosterers, 5, or 62.5 percent, were deserted. 

 Similar figures were found (Baker, 1942, p. 85) for the red-winged 

 crested cuckoo, Clamator coromandus: of 111 "normal" fos- 

 terers' nests, 1, or 0.9 percent was deserted; of 58 "unusual" 

 fosterers' nests, 4, or 6.9 percent were deserted; of 12 "abnormal" 

 fosterers' nests, 6, or 50 percent were deserted. 



In the case of the jacobin cuckoo in southern Africa no such 

 correlation has been found. In fact, the most frequently imposed 

 upon hosts in South Africa are two bulbuls, Pycnonotus nigricans 

 and P. harhatus, whose eggs are salmon to pinkish white, blotched 

 and blurred with reddish brown and grayish lavender, very different 

 from the pure white eggs of the local race of the jacobin cuckoo. 

 Yet these bulbuls accept and incubate these dissimilar eggs. Perhaps 

 the next commonest host in that area is the fiscal shrike, Lanius 

 collaris, whose eggs also differ from those of the parasite about as 

 much as do those of the bulbuls, being grayish green rather than 

 pink, but equally speckled and blotched with brown and lilac. The 

 fact that this shrike accepts the strange eggs is even more surprising, 

 as it is an aggressive bird that has been known to attack and to drive 

 off the cuckoos when they come too close to its nest. Yet, in spite 

 of this, once the eggs are deposited in the nest, the seemingly alert, 

 pugnacious host appears to be indifferent to their appearance. 



Clamator levaillantii (fig. 6, p. 22) 



The stripe-breasted cuckoo is the least known member of the genus, 

 but while the total number of observed instances of its parasitism is 

 less than that of the others, it is sufficient to show a marked preference 

 for babblers as fosterers. The Hst includes 10 species, 6 of which are 

 babblers, and which, together, account for more than three-fourths of 

 all the records. In fact, one species, Turdoides jardinei, alone, with 



