NESTS AND NEST-BUILDING IN BIRDS 179 



collectors, for Mr. H. O. Hume, at one time editor of " Stray 

 Feathers," thus speaks of their work: " Birds Hke these, which 

 build half-a-dozen kinds of nests, ought to be abolished! They 

 lead to all kinds of mistakes and difference of opinion, and are 

 more trouble than they are worth." '^ 



The arctic tern at Matinicus Rock, Maine, seems to follow no 

 rules, but a plausible interpretation of such behavior can be 

 given. With Baltimore orioles on the other hand great uniformity 

 prevails : their cradles never fill with water and drown their 



Figure 3 — Pseiulo-suspended nest of magnolia warbler, Dendroica maculosa ; rim 

 fixed to forking fir twigs, and here shown suspended to them; underlying 

 branch on which cup was molded (see fig. 5), cut away; walls thin and loose; 

 statant type of increment nest. 



progeny, and though " endlessly rocking," they are seldom torn 

 by tempests or reached by enemies. The antithesis of all these 

 conditions is presented by the terns, which are preeminently 

 social and breed in communities. The variations which they 

 present seem to be due to the inhibitory influence of the social 

 bond. The breeding cycle of this tern is clearly disturbed at 

 every point by the influence of the tern Bund or society. If 

 this is the case then variations in nest building would be pro- 

 portionate to disturbance suffered, and might possibly be greater 



" Sharpe, Boulder: Op. cit., p. 220. 



