Nest-Building 153 



corpora ted, most of this being shaken out by the treatment 

 which these received. For many hours after, this bird brought 

 mud alone about as frequently as wet or muddy grass. No 

 mortar was deliberately made either at the nest or away from 

 it, but much mixing of mud and grass was effected by the 

 kneading or molding movements, which follow each visit, and 

 as we have seen begin before they are required. That mud and 

 grass alone or mud and grass together are taken at varying 

 intervals can have no special significance. This bird would 

 bring a beakful, dispose of it, and depart so quickly it was im- 

 possible to distinguish the sex of the builder or the nature of 

 the substance carried, if the eye wandered but a moment from 

 the nesting place. Sometimes the brown grass would be drip- 

 ping wet, and the ball of earth carried in the bill larger than a 

 filbert. Once I saw a sprig of green grass taken with a large 

 lump of soil clinging to its roots. Again, a large package of 

 sodden grass would be stuffed crosswise in the full beak, or long 

 streamers of white or colored yarn trailed behind as she flew 

 to the tree, and often caught on twigs or leaves. After troubles 

 of this kind the Robin would now and then fly first to a bean- 

 pole and take up a little slack before proceeding. 



On the second day a definite habit of entering the nesting 

 tree and the nest had been acquired, a subject which the reader 

 will find more fully treated in Chapter XIII. With loaded bill 

 the bird steered straight for her tree, dropped to the horizontal 

 branch about a foot from the nest, and came to attention; then 

 if all was well she walked nimbly to the nest, stepped into it, 

 and lost no time in getting to work. After spending two or three 

 minutes or more at the molding and arrangement, she popped 

 out on the branch, brought up to attention, and slid down 

 quickly to the ground, or flying low made off for a distant field. 

 Once when a dog came sniffing through the grass, the cock from 

 his bean-pole perch gave a sharp alarm, but paid no further 

 attention and proceeded to erect and shake out his feathers. 



At every addition to the structure, as we have already seen, 

 the materials are churned and worked over afresh, and so 

 violent are some of the beating and shaking movements that 



