CUCKOOS. 



875 



possible, is the mimicry of the Droiigo-cuckoo {Surnici(li(s) of which more further on. 

 It is, probaljly, tliis simihirity to ;i li;i\vk which causes sucli comiuotioii 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 

 ujton them of rearing and educating its gluttonous and ungrateful offsjiring. 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 Avhich Mr. Seebohm jiublished 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 liabit is found in 

 many sjiecies in India and Africa, which are resident and do not migrate. Others 

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



Flo. 177. — Pterylosis of Piaya cfiyana^ ventral 

 surface. 



Fig. 17S. — Pterylosis of Ktuhtnamys orientatis^ 

 ventral surface. 



polygamous, it is polyandrous. The males arc 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 th.it its eggs arc 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 se.ison, 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 s.'ime. This power has prob.ably been gradually ac(juired 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 cxtr.aordin.ary 

 vor.acity. The sexual instincts of the male cuckoo apju'ar to be entirely subordinate 

 to his greed for food. IL' 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. lie is s.aid to be so absorbed in his gluttony that he neglects the 

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



