436 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



have found their elevation to vary from 2 to 20 feet from the ground. 

 The open cup is constructed in a variety of situations but ahnost in- 

 variably on some slender support. If some variety of citrus tree has 

 been chosen, it may rest in the angle between an upright branch and 

 one of its large thorns attached to both by cobwebs; or in another 

 kind of plant it may be placed in the axil of a slender leaf stalk or 

 in the angle between a thin horizontal branch and a vertical stem. 

 Sometimes a leaf alone suffices for its foundation. One of the most 

 attractively situated I ever found was attached near the drooping tip 

 of a large frond of the thorny pejibaye palm {Guilielma utilis) ; an- 

 other was fastened to the palmately compound leaf of the Brazilian 

 rubber tree; a third straddled the slender rhachis of the pinnately 

 compound leaf of an akee {Blighia sapida)^ supported on each side 

 by the opposite leaflets. At times the bird selects a very inadequate 

 foundation. I once found a nest attached to a frail and decaying 

 twig, which in its descent from somewhere higher in the tree had 

 caught on a horizontal branch and hung loosely beneath it, draped 

 about with the fronds of a slender, creeping species of polypody 

 fern, which covered the bough and dropped in festoons below it. The 

 one requirement of a nesting site is a horizontal support sufficiently 

 slender to be grasped by the bird's feet — for from such a perch the 

 building operations are always begun — close to some vertical or ob- 

 lique support to which the side of the nest may be anchored. Fre- 

 quently the nest is situated above or close beside a path along which 

 people are constantly passing. 



The nest is an open cup, formed exteriorly of weathered strips of 

 grass, leaves, bits of weed, fibers, and the like, and abundantly lined 

 with soft, felted plant down, the whole bound together by cobwebs 

 liberally supplied. The outer surface is tastefully decorated with 

 gray lichens and green mosses, which sometimes are allowed to 

 hang in long, waving festoons beneath it. Rarely, as in the nest I 

 found on Barro Colorado Island, this ornamentation is very sparingly 

 applied, so that the prevailing color of the exterior is grayish or 

 tawny, from the fibers and down employed in its construction. Some- 

 times an otherwise beautiful nest is marred by a long piece of with- 

 ered grass leaf, used in building the foundation, and carelessly al- 

 lowed to hang beneath it. The dimensions of a typical nest are: 

 External diameter 1% inches, height 1% inches; internal diameter 

 114 inches, depth % inch. 



The moss- and lichen-covered nests blend so well with the green 

 foliage among which they are usually placed that it would be ex- 

 tremely difficult to find them, especially when the white eggs are 

 hidden by the emerald bird, if the female sat more closely. The lo- 

 cations of several nests, which otherwise I should probably never have 



