NESTS AND NEST-BUILDING IN BIRDS 259 



The remarkable pendent nest of the Indian weaver bird 

 (Ploceus baya) consists of a grass lined globular chamber which 

 is suspended to a branch by a long fibrous cord and extended 

 below in a regular, woven tube which serves as entrance. Such 

 a nest may be used for successive years when it becomes . com- 

 pound by the addition of new chambers below the last in succes- 

 sion, until in one case recorded there were seven " stories," 

 the last of which, being made of fresh grass, probably represented 

 the nest of the current year; yet three of the lowest chambers, 

 if not in actual use, at least contained eggs. Such "infra- 

 imposed " structures are clearly comparable to the compound 

 nests of the fishhawk and eagle or even of the yellow warbler 

 already considered. 



"Double" or "triple" nests placed side by side, and more 

 or less completely joined, are rarely reported (for a beautiful 

 illustration of a double nest of the red-eyed vireo, containing 

 one and two eggs respectively and both male and female sitting 

 when discovered, see Dawson and Jones "Birds of Ohio," vol. 

 I, p. 296) ; they may be due to one of several causes, but when 

 containing eggs probably result from a disturbance of a first 

 cycle usually after a single egg has been laid, and the building of 

 a new nest beside, rather than on, the first. Such rare chances for 

 observation should not be lost by disturbing the nests, and I 

 think it will be found that the female completely abandons 

 the first, and that the ardor of the male in reference to it soon 

 dies down. 



The materials of nests and their method of arrangement. The 

 kinds of material used by birds in the construction of their 

 homes has been detailed at great length; indeed it is under 

 this head (No. 4 of analysis given above), as well as on the 

 method of arrangement and dimensions of the walls that the 

 literature of nests is most complete. The inferences which 

 have been drawn from their use of materials are not so satis- 

 factory. , 



The question of the kinds of material used by birds in nest 

 building is not very important when we consider the majority 

 of makers of increment nests. Yet there is a considerable number 

 of species which are wonderfully uniform in both their choice 

 and treatment of building materials. Between the extremes 

 every intermediate degree is to be noted. On the one hand 



