no. 3633 ALLOXENIA — FRIEDMANN 7 



the plain chocolate or olive-brown, unmarked eggs of the red-chested 

 cuckoo, C. solitarius, the commonest egg morph of that species. There 

 is, however, enough similarity among other types, especially the 

 greenish type, of the eggs of both C. solitarius and C. clamosus, to cause 

 confusion and at times to raise some doubts as to their identification. 



The eggs of C. clamosus may be said to be of three types: one with a 

 whitish ground color, one "with pale brownish, and one with a pale 

 greenish ground, all variously speckled with shades of brown and 

 gray. These types are not isolated geographically and, hence, are not 

 typical of different populations or subspecies of the cuckoo since two 

 or more occur in the same area. 



Thus, in Cameroon, Bates (1911, pi. 9, fig. 4) found an egg of the 

 race gabonensis that was pale brownish, everywhere flecked with 

 dark umber, the speckles most heavily concentrated at one pole. 

 Later (1927, pi. 2), he took another egg from a freshly shot hen, 

 which had a whitish ground color, speckled all over with reddish 

 brown and gray. From Gabon, another oviduct egg reported by 

 Schonwetter (1964, p. 545) was pale green, abundantly flecked with 

 burnt siena and gray. Still another oviduct egg from Cameroon was 

 described by Searle (1965, p. 71) as having a cream-colored ground, 

 profusely blotched and spotted with reddish-brown and with claret- 

 brown primary and ashy-purple secondary markings, all of these 

 markings coalescing near the large pole to form a ring. 



A somewhat similar greenish egg with flecks of olive brown and gray 

 was taken in Mozambique (typical clamosus), but in the same area 

 other eggs of this cuckoo were dirty white, sharply flecked with pale 

 brown and pale gray. Whitish eggs similar to these also were taken 

 in Natal and in the eastern Cape Province, South Africa (Chubb, 

 1914, p. 62; Skead, 1951a, pp. 163-173; Roberts 1963, p. 182). A 

 fairly similar egg, but less heavily flecked, taken in northwestern 

 Ethiopia by Cheesman (1935, p. 311), was described as being dull 

 white with a few reddish-brown flecks. 



As in the red-chested cuckoo, it is not possible to detect the evolution 

 of adaptive egg mimicry in the black cuckoo, but it should be noted 

 that Searle (1965, p. 71) thought that an oviduct egg of the race 

 gabonensis showed some resemblance to "certain shrike and bulbul 

 eggs." Both species of cuckoos have a considerable range of color 

 variation in their egg shells, and to that degree both have the pos- 

 sibility of developing egg adaptive gentes. The evidence available 

 clearly shows preponderant host preferences but fails to reveal pro- 

 portional egg morph specialization. Hoesch (1940) wrote that the 

 eggs of the black cuckoo tend to match those of the boubou shrike in 

 markings but not in color. Moreau (1949) considered that the eggs 

 might be looked upon as showing some color resemblance to those of 



