18 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



built in a balsam: "In its building, a framework of slender balsam 

 twigs had first been used. There were sixty- three of these, some of 

 which were as much as a foot in length. Intertwined with these were 

 twenty fragments of weed stalks and grass stems. The yellow clay 

 cup, which came next inside, varied in thickness from a quarter of an 

 inch at the rim to an inch at the bottom. Grass worked in with the 

 clay while it was yet soft aided in holding it together, and now, last 

 of all, came the smooth, dry carpet of fine grass. The whole structure 

 measured eight inches across the top; inside it was three inches in 

 width, and one and a half deep." 



Reginald Heber Howe, Jr. (1898), describes the bird's method of 

 building the nest: 



After the site has been chosen the building of a substantial foundation of twigs, 

 grasses, string, etc., is begun; this finished, finer grasses are brought and the bird 

 standing in the centre of the foundation draws them round. After the sides of the 

 nest have been fairly well made the bird by turning around in the nest shapes 

 it to the exact contour of its body, and by pushing its breast far down into the 

 nest and raising the primaries, it presses the nest with the wrist of the wing into 

 a compact and perfect mass. The next work is the plastering with mud; a rainy 

 day is generally chosen for this work; the bird brings the mud in its bill and, 

 placing it on the inside of the nest, flattens it into shape by exactly the methods 

 just described. All that remains now is the lining, which is made of fine grasses 

 and which adheres to the mud, making a substantial though not a particularly 

 beautiful nest. 



The average measurements of nest are; depth, outside, 3 inches; depth, inside, 

 2% inches; breadth, outside, 6% inches; breadth, inside, 4 inches. 



J. H. Rohrbach (1915) points out that robins may use worm casts 

 as a mud lining for their nests. He says: "A heavy rain of fourteen 

 hours' duration came just at plastering-time. Mud was abundant. 

 Then I observed what was new to me — the Robins passed by all 

 kinds of mud except the castings of earthworms, which they gathered 

 and used for nest-building." 



Katharine S. Parsons (1906) describes a nest from which hung 

 "two fringed white satin badges, fastened by mud and sticks" and 

 near them "a knot of coarse white lace" and "two white chicken 

 feathers," and Henry Mousley (1916) states that "Robins here 

 [Hatley, Quebec] are particularly fond of using pearly everlasting 

 (Anaphalis margaritacea) in the foundations of their nests." 



In early days, before the forests were cleared away, robins presum- 

 ably built mainly on horizontal limbs of trees or in crotches between 

 the branches as many robins build now in the wilder, heavily wooded 

 parts of the country, but when man felled the trees and replaced 

 them by buildings, he supplied the bird with countless additional 

 sites which afford an ample support, the chief requirement for a 

 robin's nest. Concealment, it seems, is of minor importance to the 

 robin, perhaps because it is difficult to hide so large a nest, perhaps 



