50 BIRDS' NESTS 



the normal conditions of nidification is furnished by 

 the Green Sandpiper. This species, deserting the 

 ground upon which its congeners habitually breed, 

 selects the old nest of a Thrush, a Jay, a Ring Dove, 

 or a Crow, in which to deposit its four eggs. Its 

 close ally, the Wood Sandpiper, has also been 

 recently detected breeding in similar situations, a 

 fact which seems to suggest not only that the bird is 

 changing its method of nesting, but also the manner in 

 which the habit may have arisen in such species where 

 it now more generally prevails. This is yet another 

 instance of the intelligence — reason — displayed by 

 birds in the matter of nesting, as opposed to the 

 theory of an unchanging and unvarying instinct. 

 Some of the Swallows {Tachycincta) make their nests 

 in the deserted holes or nests of other birds. 



Before leaving this particular branch of the sub- 

 ject, it may be as well to refer to the peculiar habit 

 which some birds possess of making their nests 

 inside the structures belonging to other species. 

 Some of these are what may facetiously be termed 

 the guests of larger birds. The Great Titmouse 

 (Parus major), for instance, not unfrequently makes 

 a domed nest in the interior of the disused abode 

 of a Crow or a Magpie ; whilst I have known it to 

 build its nest amongst the sticks in the foundation of 

 a Rook's nest, whilst the latter was occupied. The 

 House Sparrow will also sometimes select a similar 

 situation ; whilst in North America both this species 



