268 LIFE HISTORIES OF NORTH AMERICAN BIRDS. 



bii'ds an abundant supply of suitable building material, of which they promptly 

 availed themselves. While the walls in some nests are thick and well lined, in 

 others there is but little attempt at lining the sides of the cavity, and only a 

 small amount of hair is placed in the bottom of the hole on which the eggs are 

 deposited. It depends entirely on the araoimt of room, and it is surprising how 

 little space is really required by them in which to rear a family. The inner cup of 

 a well-preserved nest of this Flycatcher, placed behind a loose piece of bark of an 

 old Cottonwood stump, measures about 2 J inches in diameter by 2 inches in depth. 

 The walls of this nest are composed exclusively of cattle hair, which is well 

 quilted together and forms a fairly strong felt. The base is formed of dry grass 

 roots, and it was placed between the soft inner and the outer bark of the tree, 

 which kept it intact and held it firmly in position. 



I discovered the first nest of this species in a dense piece of mesquite woods 

 on May 26, 1872, and between this date and June 24 I found fifteen others, with 

 eggs, and several with young birds, some of these being fully fledged. Not one of 

 these nests contained more than four eggs, quite a number only three, and I do 

 not believe that more than one brood.is raised in a season. The female, I think, 

 attends to the duties of incubation exclusively, which lasts about fifteen days. 

 She is not a close sitter, and often leaves the nest for hours, especially during the 

 heat of the day, but remains close by. The young are fed on the soft portions 

 of insects, and leave the nest in about two weeks, following the parents about for 

 some time before they are able to care for themselves. This Flycatcher leaves 

 for its winter home about the latter part of September. 



The number of eggs to a set ranges from three to six, but sets of the latter 

 number are very rare; four are more frequently found; and an egg is deposited 

 daily. The ground color varies from a light cream to a pinkish buff, and this is 

 covered more or less profusely with fine longitudinal streaks and hair lines of 

 dark purple and lavender, rarely with large, irregularly shaped blotches. The 

 general pattern of these matjkings is finer than in the eggs of Myiarclius crinitus, 

 and the majority can be readily distinguished from those of the latter, but not so 

 easily from the lighter-colored types of Myiarclius mexicanus. In shape they 

 vary from ovate to elliptical ovate. The shell is fine-grained, rather strong, and 

 slightly glossy. 



The average measurement of fifty-four eggs in the United States National 

 Museum, collection is 22.40 by 16.51 millimetres, or about 0.88 by 0.65 inch. 

 The largest egg of the series measures 23.88 by 17.78 millimetres, or 0.94 by 

 0.70 inch; the smallest, 20.32 by 15.24 millimetres, or 0.80 by 0.60 inch. 



The type specimen, No. 25218 (PI. 2, Fig. 13), is from a set of five eggs, 

 and was taken by First Lieut. Harry C. Benson, United States Army, in Sequoia 

 National Park, Tulai-e County, California, on May 25, 1892. 



