KHASIA HILLS CUCKOO 93 



her young, while all cuckoos, as well as the foster parents, are affected 

 more or less in tlieir spring migration and breeding time by the late 

 or early arrival of the rains and the consequent shortage or abund- 

 ance of insect life. In Assam, where the rainy season is long and 

 the rainfall heavy, eggs may be found in some numbers from April 

 20 to the middle of June and, then, in decreasing numbers, to the end 

 of June, after which they further decrease in number until, after the 

 middle of July, few will be taken, though my latest recorded date for 

 a cuckoo's egg is August 24. In Burma, as already noted, birds 

 commence laying about a month earlier, and few eggs are found after 

 early June. 



The 1,366 eggs in my collection were taken as follows : One in ISIarch 

 (taken in Burma), 104 in April, 608 in May, 527 in June, 114 in July, 

 and 12 in August. It may, I think, be accepted that migrating 

 birds arrive on their breeding ground some two to three weeks before 

 commencing to lay and leave again about one to two months after the 

 deposition of their last eggs. 



In Burma the peak of laying is reached in early May; in Assam 

 not until the end of that month. 



Courtship. — I can find nothing recorded as to the conduct of court- 

 ship between males and females during the breeding season and have, 

 therefore, only my own observations to guide me. There appears to 

 be no true courtship, and I have no doubt that, except in very rare 

 instances, cuckoos do not pair, though in certain areas, where the 

 bird is uncommon, a male and female may possibly mate and remain 

 together throughout the breeding season. This is probably the case 

 in North Cachar, where the bird is rare, breeding in deeper forest 

 than I have seen anywhere else, and where I have seldom heard 

 more than one male calling in any one particular area or found more 

 than one type of egg deposited therein. In the Kliasia Hills, in 

 which district the birds swarm in incredible numbers, both sexes 

 were undoubtedly promiscuous in their sexual relations. I have 

 personally seen a female accept the attentions of one male and then 

 fly off to a tree close by and accept another pursuing male within a 

 few minutes. On this occasion several, I think four, males were 

 pursuing the one female, who flew slowly from one tree to another 

 on a roadside. Settling on one of these she crouched on a large 

 bough, half lying there with both wings hanging slightly lowered 

 and quivering, while her head was held quite low, her whole attitude 

 expressing invitation. The first male, of those following her, at once 

 accepted this after which he settled on a branch close by while the 

 female flew away to a tree about 50 paces distant followed by the 

 other three males, one of whom was again accepted by the female 

 who, after the completion of the act flew off accompanied by the 

 remaining two males to a tree beyond my view. 



