6o SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I46 



ground below the nest; the following day another egg was found 

 there ; still 4 days later the drongo chick, which had hatched in the 

 meantime, was lying below the nest. The finding of these eggs and 

 of the nestling drongo under the nest suggested (but only suggested) 

 that the eviction was done by the young parasite. Skead was careful to 

 point out that this inference required proof. 



The estimated age of the young cuckoo was three days when the 

 first of the host's eggs was found below the nest, and 8 days when 

 the drongo chick was so recorded. If the eviction was done by the 

 young cuckoo, this would imply a much longer duration of the 

 evicting instinct than occurs in Cuculus, a genus in which the habit 

 is well established. 



It is impossible to state that the young cuckoo was not responsible, 

 but there are other cases known where eviction definitely did not 

 take place. Skead himself (1951, pp. 172-173) described a case in 

 which a nestling jacobin cuckoo tolerated eggs and young in the 

 same nest for up to 4 days, and another nest in which another young 

 parasite made no attempt to evict the eggs for 4 days during which 

 the nests were under observation. It not infrequently happens in a 

 crowded nest that activity by one of the nestlings may sometimes 

 result in the accidental pushing of one of the eggs or young out of 

 the nest. Also, in parasitized nests, the young parasite often is larger 

 and grows relatively faster than its nestmates and by successful com- 

 petition with them for the food brought by the adults may starve them 

 to death. In such cases the dead young are removed, not by the young 

 parasite, but by their own parents as a matter of nest sanitation. 



Furthermore, there are observations of still other nests in which 

 the host young and the young jacobin cuckoo grew up together to the 

 fledgling stage, and were seen together even after leaving the nest 

 (Godfrey, 1939, p. 3; Bates, 1938, p. 125). These are clearly cases 

 in which no eviction by the young parasite took place. In the two 

 instances described by Skead, if any eviction by the young cuckoo 

 might have been involved, it did not occur for some days after hatch- 

 ing, which is not the case in Cuculus. On present evidence it is doubt- 

 ful that young Clamators have the habit of methodically and deliber- 

 ately ousting their nestmates during the early stages of their nestling 

 hfe. 



An unusual type of host-parasite nestling relations was observed in 

 India by MacDonald (1960, pp. 174-175). He watched a nest of a 

 jungle babbler, Turdoides striatus somervillei, that contained a nest- 

 ling jacobin cuckoo and a young babbler. The young parasite was 



