THE CUCKOO’S SECRET 
once more returned. Although this was the first 
egg found this year of Cuckoo A, I am reasonably 
certain that it was the second actually laid and 
equally sure that it was laid on this day. 
On May 19 a second egg of Cuckoo A was 
found in a Meadow Pipit’s nest (No. 9 pair) with 
one egg. 7 p.m. was the hour of discovery, and 
I am convinced that the egg was the fourth of the 
series to be laid, and that on this day. 
On May 20, at 8 p.m., a third egg of Cuckoo A 
was found in a Meadow Pipit’s nest (No. 4 pair) 
with four of the fosterer’s eggs. By all available 
evidence, such as stage of incubation, and the light 
of subsequent experience, this egg of Cuckoo A 
was the first of this year’s series and was laid on 
May 13. The nest was within four yards of the 
Linnet’s nest containing the egg of Cuckoo B, 
which we had found on the 15th. The incident 
illustrates how narrowly we then failed to find this 
nest, and how easy it is to overlook a nest. Hence 
the value of our “ double-check ” system (sec p. 37). 
On May 21 a fourth egg of Cuckoo A was 
discovered at 11 a.m. in a Meadow Pipit’s nest 
(No. 6 pair) with three eggs. There is no doubt 
in my mind that it was laid on the 17th, thus being 
the third egg of the series. 
