Humming-birds as Engineers 223 



the way in which they seem to adjust the balance of their 

 suspended nests is wonderful. Thus Mr. John Gould, who 

 made a life-long study of these birds, remarks — " Some of 

 the Humming-birds are said to suspend their nests by the 

 middle from the fine hanging roots of a tree, or a tendril ; 

 and should the nest, which is of a curved form and built of 

 any coarse materials at hand, prove to be heavier on one 

 side than the other, the higher side is weighted with a small 

 stone or square piece of earth until an equilibrium is 

 established and the eggs prevented from rolling out. If 

 such powers, so nearly approaching to 

 that of reason, should be doubted by 

 some of my readers, I can assure them 

 that one or more of these loaded nests 

 are in the Loddigesian collection, and 

 one is at this moment before me, as I 

 write, an examination of which will 

 satisfy the most sceptical of the truth 

 of this statement." 



The subjoined illustration represents 

 a nest of the Pichincha Hill-star (Oreo- 

 trochilus pichincha) preserved in the 

 Natural History Museum. It has often 

 been figured as a curiosity since it was first discovered by 

 Fraser on the volcano of Pichincha in Ecuador. The nest 

 was attached to a straw rope hanging to the roof of a house 

 which was situated at an elevation of 13,450 f eet above the 

 sea-level. It is a compact mass of wool and hair mixed 

 with dried moss and feathers. A little cup-shaped opening 

 at the top forms the receptacle for the eggs, and is balanced 

 and brought into position by the weight of the moss on 

 the opposite side of the rope by which it is suspended. 1 



Other instances of the intelligence of the Humming-bird 

 as a nest-balancer have been recorded. Thus Professor 



1 See the 'Proceedings of the Zoological Society for i860,' p. 80. 



Nest 



Oreotrochilus pi- 

 the British 

 Museum, from Ecuador. 



chincha, 



