i86 
THE CUCKOO’S SECRET 
as may be permitted by other hen Cuckoos. And 
where there are hen Cuckoos, it is only natural to 
expect to find male Cuckoos there too. It is the 
custom with at least many hen Cuckoos annually 
to return to the territory occupied in the previous 
season, and it is more than probable that competi- 
tion for the best breeding areas is keen. It is likely 
that individual Cuckoos not endowed with a domi- 
nating nature fare but poorly in their reproductorv 
efforts, and instead of depositing a large series of 
eggs in a season may have to content themselves 
with a very small number indeed. 
Fortunately, the facts which I have set forth 
concerning the Cuckoos A, B, E, and F, one or 
more of which appeared on the common during 
the four seasons 1918-21, serve admirably to 
illustrate my points. In the first season we have 
A, which I take to have been then a young bird 
— for in 1916 she was certainly not there — in 
sole possession until some time about the begin- 
ning of the second week in June. Then, as A’s 
period of laying activity is on the wane, B appears. 
On more than one occasion we find both Cuckoos 
making use of the same fosterer’s nest, and if it 
were A’s first season, I would not expect her to rid 
herself entirely of B. But I have yet to experience 
