42 THE WATER OUZEL 



that unless the bird is watched, or accidentally- 

 put off, it is next to impossible to find the nest ; 

 even when the bird has been started, it takes 

 some time to discover the edifice. But the 

 owner has no difficulty in finding it ; she comes 

 straight home to the very spot. In pure 

 nature there never is any question of losing 

 the way ; creatures return naturally to the 

 domicile of whatever description ; but if, in 

 the meantime, the habitation has been inter- 

 fered with or moved from the original site, 

 the creature is baffled, and only by chance 

 discovers it. 



Although some of nature's schemes are 

 difficult to follow, there are others which speak 

 for themselves. For example, the water ouzel, 

 a bird which belongs to the same order as the 

 blackbird, builds a blackbird's nest, but she 

 covers it with a roof. Why? Because the site 

 is always a damp situation (generally under a 

 bridge or overhanging rock), and the mossy 

 dome protects the nest from the continuous 

 drips of water. 



I have always thought this a particularly 

 notable instance of subconscious foresight. 



Another remarkable example of nature's 

 foreknowledge is shown in the case of the 

 Crowned-Hornbill (Lophoceros melanoleucus), 

 a South African species. This bird nests in the 



