NO. 4 AVIAN GENUS CLAMATOR — FRIEDMANN 79 



It is among the cuckoos, purely insectivorous in their feeding, 

 that we find some of the most remarkable of geographic migrants. 

 We may take, as an example, the long-tailed cuckoo, Urodynamis 

 taitensis, that makes an unusually long, and largely nonstop, over- 

 seas journey from its New Zealand breeding grounds to the islands of 

 Polynesia, some of which are as much as 4,000 miles away. (Bogert, 

 1937). Another notable example is the little bronze cuckoo, Chryso- 

 coccyx hicidus, also a New Zealand bird, that goes more than 2,000 

 miles across the South Pacific to the Solomon Islands (Fell, 1947). 

 The common cuckoo of Europe makes a similarly impressive journey 

 from its northern breeding area to tropical and even to southern 

 Africa. In fact, numerous writers have made particular mention of 

 the fact that the young of the year of this species make this spectacular 

 trip by themselves with no possible aid from, or accompaniment by, 

 the adults of their own kind, with whom they have had no experi- 

 ence. 



The concepts of migratory tendencies, even if they are not more 

 than a periodic psychobiological restlessness, originally not rigidly 

 correlated with, or controlled by, heredity, and of migration apart 

 from the rigid seasonal climatic fluctuations of Pleistocene glaciation- 

 induced patterns, make it possible to look upon the Clamator situation 

 as less enigmatic and less paradoxical than it first seemed to be. Con- 

 sidering the pronounced migratory tendencies of its relatives in the 

 subfamily Cuculinae, it would be surprising if the species of Clamator 

 were not also somewhat migratory. The extent to which this behavior 

 is developed differs in the four species of the genus. To explore these 

 differences further, we may now turn to the situation in each species, 

 as far as the present, still incomplete, data will permit coordinated 

 presentation. 



Clamator jacobinus 



It is definitely known that the population (subspecies serratus) 

 that breeds in Natal, Transvaal, Cape Province, and Southern Rho- 

 desia, is absent from those areas from late March to October (south- 

 ern "winter") , and that individuals of the pale morph of this race have 

 been collected during these months in Nyasaland, in the open grass- 

 lands of the southern and eastern parts of the Republic of the Congo, 

 former Belgian Congo, (Aru in the Upper Uele, Mahagi Port in the 

 Ituri, and near the base of Ruwenzori) and in Uganda (Mohokya, 

 Fajao, and Kebusi in May, Butiaba in November). In Darfur, Lynes 

 (1925, p. 354) found serratus (recorded by him as jacobinus, but 

 corrected by Jackson and Sclater, 1938, p. 497) in June and August. 



