570 NORTH AMERICAN BIRDS. 



large enougli to receive one acorn at a time. Tliey are packed in, one above 

 the other, until the cavity is full. How did tlie.se W()()d])ecivers lirst learn 

 to tluLS use these storehouses, by nature closed against them ? The intelli- 

 gent instinct that enabled this bird to solve this problem Saussure regarded 

 as not the least surprising feature. AVitli its beak it pierces a small round 

 hole through the lower jiortion into the central cavity, and thrusts in acorns 

 until the hollow is lilled to the level of tlie hole. It then makes a second 

 o])ening higher uj), and fills the sjjace below in a like manner, and so pro- 

 ceeds until the entin; stalk is full. .Sometimes the space is too small to re- 

 ceive the acorns, and they have to be forced in by blows from its beak. In 

 other stalks there are no cavities, and then the Woodpecker creates one for 

 each acorn, forcing it into the centre of the ])ith. 



The labor necessary to enable the bird to accomplish all this is very con- 

 siderable, and great industry is reipiired to collect its stores ; but, once col- 

 lected, the storehouse is a very safe aiK convenient one. iVIount Pizarro is 

 in the midst of a barren desert of sand and volcanic debris. There are no 

 oak-trees nearer than the Cordillera.?, thirty miles distant, and therefore the 

 collecting and storing of each acorn required a flight of si.xty miles. 



This, reasons Saussure, is obviously an instinctive preparation, on the 

 part of these birds, to provide the means of sujjporting life during the arid 

 winter months, when no rain falls and everything is parched. His observa- 

 tions were made in A])ril, the last of the winter months ; and he found 

 the Wood])eckers withdrawing food from their depositories, and satisfied 

 himself that the birds were eating the acorn itself, and not the diminutive 

 maggots a few of them contained. 



The ingenuity with which the bird managed to get at the contents of each 

 acorn was also quite striking. Its feet being unfit for grasping the acorn, it 

 digs a hole into the dry bark of the yuccas, just large enough to receive the 

 small end of the acorn, which it inserts, making use of its bill to si>lit it 

 open, a;i with a wedge. The trunks of the yuccas were all found riddled 

 with these holes. 



There are several remarkable features to be noticed in the facts observed 

 l)y Saussure, — tlie provident instinct which prompts this bird to lay by 

 stores of provisions for the winter ; the great distance traversed to collect 

 a kind of food .so unusual for its race; and its seeking, in a spot so remote 

 from its natural abode, a storehou.se so remarkable. Can instinct alone 

 teach, or have experience and reason taught, these birds, that, better far than 

 the bark of trees, or cracks in rocks, or cavities dug in the earth, or any 

 other known hiding-place, are these hidden cavities within tlie hoUow stems 

 of distant plants ? What first taught them liow to break through the flinty 

 (coverings of these retreats ? By what rev(!lation could these birds have 

 been informed that within these dry and closed stalks they could, by search- 

 ing, find suitable places, protected from moisture, for preserving their stores 

 in a state most favorable for their long preservation, safe from gnawing 



