FOSTERERS OF THE CUCKOO 201 
the Cuckoo laid on the nest when she hopped into 
the hedge and disappeared from view for about a 
minute. Very possibly she was really not there 
nearly so long as a minute, judging from the speedy 
laying performances of our Meadow Pipit Cuckoos. 
In the fourth volume of his Vogel Mitteleuropas 
Naumann states that he saw a Cuckoo lay its egg in 
a Reed Warbler’s nest, and further that it held itself 
in position by pressing its wings and tail against 
the reeds surrounding the nest. There cannot be 
much doubt about the accuracy of this observation, 
if only for the reason that it would scarcely have 
occurred to Naumann to make the statement with 
such detail unless he had witnessed the happening. 
When Reed Warblers’ nests contain Cuckoos’ 
eggs they are almost invariably tilted sideways. 
This could, of course, very well come about from 
the Cuckoo standing on the rim to deposit her egg 
with her bill. But my reading of it is that the tilt 
is caused either by the Cuckoo “ taking-off ” after 
laying on the nest, or, as is perhaps even more 
probable, by the downward pressure of the Cuckoo’s 
tail in the act of laying, which is so clearly illustrated 
in the film photographs. Whether she backs out as 
she does from Meadow Pipits’ nests or goes straight 
forward, the flimsy nest is not usually strong enough 
