NESTS AND NEST-BUILDING IN BIRDS 261 



tunate passenger on one of the Fall River boats, and seen in the 

 talons of the hawk when under way to its nest, all come as 

 perfectly to the hand of this beach comber, as the store of soda 

 bottle wires picked up in a back yard, or the entire stock of 

 steel spectacle frames, stolen from an optician's window in 

 Calcutta or Bombay, suits the tastes of the unconventional 

 crow, or indeed as the five or six green leaves or as many pebbles, 

 at times satisfies the simpler tastes of the arctic tern at Matinicus 

 Rock, Maine. 



Again were w^e to examine a series of nests of either the ruby 

 throated humming bird, the red eyed vireo, the Baltimore 

 oriole, or even of the robin we should have to admit that the 

 range of choice in the selection of materials had been narrowed 

 greatly with correspondingly greater uniformity in their treat- 

 ment. Indeed we approach more nearly the wonderful uniformity 

 displayed by the mud and paper nests of wasps, and the pris- 

 matic wax cells of the honey bee, an unmistakable index of the 

 more complete sway of instinct in guiding the actions of the 

 builders. We might add that the crow and his tribe, which are 

 generally regarded as the most intelligent of birds, can seldom 

 be trusted in the presence of any bright or shining objects 

 whatsoever which they will carry off and either hide or work into 

 ^their nests. 



The nest of the common robin forms as good a text as any 

 from which to view this subject, and we shall later see how it 

 is built. Probably in not one nest in a thousand, examined by 

 interested persons, have the conditions under which it was built 

 been accurately known; yet it is these conditions, such as the 

 state of the weather, the nature of the site, and the character 

 of the general environment, not to speak of the synchronization 

 of the instincts, which mainly determine the character of such 

 nests ; the more uniform the conditions the more stereotyped the 

 result. Upon a foundation of dead weeds and stubble this bird 

 usually raises a clay cup; the softened mud and other materials 

 are well incorporated to form a consistent mortar, and a lining 

 of finer grass is usually added. Now either a lack of suitable 

 materials, as in times of drought, or of the proper instinct 

 causes some robins to dispense with the mud cup, while pro- 

 longed rains hamper all which build in exposed situations, and 

 melt dow^n their walls as fast as they can raise them. Where 



