242 SAYORNIS FUSCUS, PEWIT FLYCATCHER. 



nests of our common Phoebe-bird, Sai/or)iis fusem, which in size, struc- 

 ture, aud materials, mij?ht be taken for nests of species distinct from the 

 one under consideration. As these nests were found upon the horizon- 

 tal beams of a wagon-shed, they would not seem to require such com- 

 pactness of structure as wheu built in more exposed situations. 



"After a careful examination of several nests from different localities, 

 I find that they are usually cir(;ular at the top, with a depth externally 

 differing but little from the average diameter. By measurement 1 

 obtain the following dimensions: Diameter from side to side, 3^ inches, 

 depth 3 inches ; diameter of cavity within, 2i inches, making the thick- 

 ness of the lateral walls ^ inch ; depth of cavity, 1^ inch, indicating a 

 thickness at the bottom of li inch. These nests are composed of fine 

 roots, grasses, fine mosses, and hairs, which are plastered together, and 

 to the objects upon which they are built, by pellets of mud ; within they 

 are lined with soft grasses, lint, hairs, aud sometimes with wool, and 

 feathers. 



"No. 1 of deviation is nearly circular, with an average diameter of 4 

 inches and a depth of 2 inches, being considerably depressed. Diame- 

 ter of cavity 2^ inches, depth 1 inch ; thickness of lateral walls f inch, 

 at the bottom 1 inch. The nest is constructed wholly of the silk of 

 corn, with a few strings and hairs on the inside for a lining ; the absence 

 of moss and clay pellets being a noticeable feature of the nest ; such 

 ordinarily indispensable materials evidently not being requisite, if the 

 site of the nest affords any criterion for judging. 



"No. 2 of these anomalous forms is circular, with a diameter of 5 

 inches, and a depth of 2t} inches on the outside; within, 2^ inches in 

 diameter and 2 inches in depth ; lateral walls, 1| inch in thickness ; in- 

 ferior, ^ inch. The entire nest is composed of the inner bark of the 

 chestnut, plucked, doubtless, from fence rails, and reduced to very tine 

 strips for the inner part of the nest, aud gradually attaining a width of 

 nearly one-fourth of an intjh on the exterior. 



"In an intermediate form between the ordinary form and the first de- 

 viation therefrom, I find the diameter 4i inches externally, depth 2 

 inches; cavity 2.] inches, and depth 1^ inch ; lateral walls, each, 1 inch ; 

 inferior, v} inch. This nest is formed of fine grasses, hair, wool, and an 

 abundance of moss externally ; within it is lined by fine grasses and 

 hairs ; the absence of clay would seem to imply an unexposed ])lace for 

 its site, to which theory looseness of its structure most assuredly adds 

 weight. 



"That a species which has always been known to build a nest so char- 

 acteristic as the Pewee should deviate so considerably and suddenly, 

 as it seems to be, from its ordinary habit of nest-building, is remarka- 

 ble. But such is the fa(;t, as the mother-bird was discovered in the act 

 of incubation. It has been suggested that possibly these nests were 

 stolen })ro[)erty, and not the woik of the bird in question. But this, I 

 am satisfied, is not the case. The individuals of some species do take 

 forcible possession of the abodes of others, or the cavities in which 

 such are secreted, but I have never known the intruders to occupy the 

 same, except in the case of Molothrus peeoriH of America, aud Cuculm 

 canontfi of England. As these birds never build, but deposit their eggs 

 in the nests of other birds, I am hardly dis])osed to grant the propriety 

 of considering them in this light. It is well known that Troglodytes 

 aedon does, when prompted by a mischievous si)irit, drive away Icterus 

 baltiinore aud Sayornis fuscus from their rightlul ]>roperty, and take up 

 her abode therein, but not without having j>reviously constructed her 

 rude nest of coarse sticks, well lined with feathers and down. 



