240 WILD BIRDS 



instantly in almost any light, and here they are seen 

 as they are not seen on the plumage of the swan 

 and grebe without the aid of glasses. 



THE WREN'S NEST 



Nest making by the cock wren in April is so usual 

 that I have wondered whether the hen bird builds 

 at all early in the season. If you find an empty 

 wren's nest in April, the chances are it is the work of 

 a cock bird. But the building of the cock wren 

 by no means ends in April. He is still building all 

 by himself in the middle of May, probably later. 

 Now, before the leaf is thick, is the time to find these 

 beautiful nests, and to watch the architects at work. 

 It is not hard, when we know the haunts and habits 

 of wrens, to find the nests and see the singular cock- 

 tailed little things fetching and carrying the material, 

 constantly popping in and out of the tiny, round, 

 dark entrances. Once the outside of the nest, how- 

 ever, is complete, we cannot get a good glimpse of 

 the builder arranging and pressing into place his 

 material : the most we can hope to see through the 

 entrance at very close quarters is some quick, 

 shivering little movements, the meaning of which is 

 not clear to me. I know of a nest in the dark fir 

 wood, another in the hornbeam hedge. That in 

 the fir wood hangs about eighteen inches from the 

 ground, among dead stems and litter of larch : it 

 matches almost exactly its environment in colour 

 grey and brown but otherwise is rather noticeable, 

 a ball of dead leaves and moss hanging in very thin 



