62 OUR BIRD ALLIES. 
THE closely-allied Willow Warbler is also a great 
destroyer of insects, and, being less given to invading 
the fruit-garden than the whitethroat, is perhaps even 
more distinctly a beneficial species. It generally 
arrives in this country towards the middle of April, 
and within a few days of that time its cheery little 
song is almost sure to be audible in its favourite 
haunts. 
The nest of this bird is generally very carefully 
concealed, and often gives even an experienced nest- 
hunter some littletrouble before he can detect its exact 
whereabouts. I well remember on one occasion 
putting up a willow warbler from among some long 
grass, and, as the bird rose almost from beneath my 
feet, I felt convinced that she had left her nest. This, 
however, a long and careful search failed to detect, 
and I was just upon the point of leaving the spot 
when my hand_ slipped from a small hillock upon 
which it had been resting and came into contact with 
the eggs. I then found that the bird had not only 
built a domed nest, after its usual fashion, but had 
furthermore constructed, by way of approach, a 
tunnel of some little length, by carefully fastening the 
grass stems together at three or four inches from the 
ground. And so carefully had it performed the 
operation, and so well was the nest concealed, that, 
had it not been for my accidental slip, I am quite 
sure that my search would have proved unavailing. 
THE graceful little Wood Warbler, which strongly 
resembles the preceding species both in appearance 
