10 
THE CUCKOO’S SECRET 
My first awakening to the possible revelations 
which might be the reward of any one prepared to 
devote sufficient time and patience to the watching 
of the Cuckoo came through reading an article by 
E. E. Pettitt in Wild Life for 1915. In that paper 
the writer gave an account of his investigations 
amongst Cuckoos parasitic upon Reed Warblers,* 
showing that individual hen Cuckoos occupied 
particular breeding areas, usually of no great 
extent, in which they deposited their eggs. This 
conclusion was arrived at through noticing that 
eggs of any one type were always found in a given 
area and never in others. 
Subsequently I came in contact with my friend 
O. R. Owen, of Knighton, who had, in the year 
1916, found a number of eggs of several Cuckoos 
in nests of Meadow Pipits ( Anthus pratensis , L.). 
Having myself also acquired some direct evidence 
of the accuracy of the territorial theory as applied 
to the Cuckoo, I began, in 1918, a close study of 
the bird, choosing for my scene of operations a 
small common in one of the Midland counties, 
where, two seasons previously, a Cuckoo had been 
found to be victimising the Meadow Pipits thereon. 
My observations have been continued during each 
* Acrocephalus strepcrus. 
