CUCKOOS. 



375 



possible, is the mimicry of the Drongo-cuckoo (Surniculus) of which more further on. 

 It is, probably, this similarity to a hawk which causes such commotion among the 

 smaller birds when they become aware of the cuckoo's presence, rather than an in- 

 stinctive recognition of the cuckoo as the parasite which imposes the heavy burden 

 upon them of rearing and educating its gluttonous and ungrateful offspring. We 

 have here arrived at the very vexed questions relative to the reproduction of the 

 cuckoo, of which so much has been written and so little is known. We can certainly 

 do no better than give extracts of the summary which Mr. Seebohm published in 

 1884 in his excellent work on English birds and their eggs. 



" The cause of this curious habit is very difficult to discover. It has been suggested 

 that the hereditary impulse to leave its breeding-grounds so early originally obliged 

 it to abandon the education of its young to strangers ; but the same habit is found in 

 many species in India and Africa, which are resident and do not migrate. Othei'S 

 have attributed it to the polygamous habits of the cuckoo, but the cuckoo is not 



FIG. 177. Pterylosis of Playa cayana, ventral 

 surface. 



FIG. 178. Pterylosis of Eudj/namys orientalis, 

 ventral surface. 



polygamous, it is polyandrous. The males are much more numerous than the females. 

 The sexes do not pair, even for the season. It is said that each male has its own 

 feeding-grounds, and that each female visits in succession the half dozen males who 

 happen to reside in the neighborhood. A plausible explanation of the peculiar habits 

 of the cuckoo is to be found in the fact that its eggs are laid at intervals of several 

 days, and not, as is usual, on successive days. Very satisfactory evidence has been 

 collected that the cuckoo lays five eggs in a season, and that they are laid at intervals 

 of seven or eight days ; but the American cuckoo and many of the owls very often 

 do the same. This power has probably been gradually acquired by the cuckoo, so as 

 to give the female time to find a suitable nest in which to deposit each egg. It is 

 possible that this singular habit of the cuckoo has arisen from its extraordinary 

 voracity. The sexual instincts of the male cuckoo appear to be entirely subordinate 

 to his greed for food. He jealously guards his feeding-grounds, and is prepared to 

 do battle with any other male that invades them, but he seems to be a stranger to 

 sexual jealousy. He is said to be so absorbed in his gluttony that he neglects the 

 females, who are obliged to wander in search of birds of the opposite sex, and appear 



