EARTH AND SALT AS FOOD 99 



race at the Zoo do the same ; but I do not know 

 if this is done by wild birds. M. G. Rogeron in his 

 admirable work " Les Canards," credits Ducks with 

 being able to extract nutriment from earth ; he 

 points out how eagerly tame Ducks ransack rain- 

 puddles in a road after a shower, where there can 

 be no animal or vegetable food to attract them, 

 and recommends that earth be placed in the pans 

 of water supplied to young Ducks which are being 

 reared in confinement. 



I myself have seen Mallard in Hyde Park on a 

 wet day bibbling assiduously in a puddle on the 

 path, and though Ducks when doing this may be 

 only getting gravel, it would not be so very remark- 

 able if they and other birds could utilize earth as 

 food, as we well know this to be done by earthworms, 

 whose digestive organs are very like those of a bird 

 in miniature, with a crop and a gizzard stocked 

 with minute particles of grit all complete. 



It is not surprising that salt is liked by some 

 birds, seeing the craving for this mineral is so widely 

 spread ; it is chiefly consumed however by vegetable 

 feeders such as Parrots and Pigeons, the last being 

 particularly keen on it. The Wood-Pigeon will 

 drink salt water in order to obtain it ; and whether 

 it is liked or not, salt water must be drunk by the 

 purely sea-birds such as Penguins, Auks, Petrels and 

 marine Ducks like the Eider. Gulls, however, will 

 come to fresh-water pools if they have the chance 

 in order to drink the fresh water. 



Many birds, however, are curiously indifferent 



