TRAILL'S FLYCATCHER. 311 



more open, sagebrush-covered valleys in the interior, where it seems to be 

 replaced by Empidonax pusiUus, or intermediates, which are not readily referable 

 to either form. In fact, the differences between these birds are, at best, but very 

 slight, and the easiest solution would be to recognize only one species. 



Traill's Flycatcher usually makes its appearance in the more southern parts 

 of its breeding range about the latter part of May or during the first ten days in 

 June, and correspondingly later farther north. While collecting in company 

 with Dr. William L. Ralph, in the vicinity of Wilmurt, Herkimer County, New 

 York, on June 23, 1893, we found a nest of this subspecies in a swampy pasture, 

 placed in a small arrow-wood bush about 2 J feet from the ground. 



The nest of Traill's Flycatcher resembles that of the Little Flycatcher very 

 much, and, like it, is nearly always built in a crotch formed by two or more 

 twigs growing out from the main stem; occasionally it is placed on a horizontal 

 limb, at a point where several smaller twigs spring out perpendicularly from it; 

 around these the walls of the structure are often woven. As a rale they are 

 well constructed, the materials used varying somewhat in different localities, dry 

 grasses, pine needles, shreds of bark, and plant fibers usually constituting the 

 body of the nest, the inner cup being lined with fine grass tops, shreds of bark, 

 vegetable fibers, fern down, and occasionally with a few horsehairs. A typical 

 nest measures about 3 inches in outer diameter by 2 J inches in height; the inner 

 cup is about 2 inches wide by 1| inches deep; the materials composing it are 

 well interwoven with each other; the outer walls are thick, and, as a rule, it is 

 well concealed. 



I have seen it stated that Traill's Flycatcher occasionally builds a semipensile 

 nest, like the Vireos, but I have never seen any, and such instances, if they really 

 occur, must be rare. Its nest appears invariably to be placed in low shrubs or 

 bushes near water, and rarely over 6 feet from the ground, more often from 1 to 

 4 feet. 



Nidification begins late in the season, about a week being consumed in nest 

 building. The eggs, from two to four in number, usually three, although sets of 

 four are not uncommon, are deposited daily. In the more southern parts of 

 their range fresh eggs may be looked for in the last half of June, while in the 

 more northern portions, generally during the first two weeks in July. 



A single brood is raised in a season, incubation lasting about twelve days. 

 The Cowbird occasionally deposits an egg in the nest. The young are fed on 

 insects, and leave the nest in about two weeks. The return migration to the 

 south begins sometimes in the latter part of August, but usually during the first 

 half of September, and none winter within our borders. The eggs are mostly 

 ovate in shape; the shell is close grained and without luster. The ground color 

 ranges from a pale creamy white to a pale pinkish buff. The markings vary 

 considerably in size from minute dots and specks to bold spots and blotches of 

 cinnamon rufous, ferruginous, and claret brown, and they predominate mostly 

 about the larger end of the egg, in some cases forming an irregular wreath. A 

 few specimens are very slightly marked and appear ahnost immaculate. On 



