156 LIFE HISTORIES OF NORTH AMERICAN BIRDS. 



this species raises two broods a year, at least throughout the southern portions 

 of its range. It did not appear to be common on these plains, but in the foot- 

 hills its calls were much more frequently heard. 



The eggs of Nuttall's Poor-will were first discovered by Dr. G. Suekley, 

 on July 17, 1859, on the North Fork of the Platte River, in western Nebraska, 

 and an egg of this set is at present in the United States National Museum 

 collection. I find that it had been correctly entered, but its existence had 

 evidently been overlooked, as no mention of it is made in the "History of 

 North American Birds, 1874," by Baird, Brewer, and Ridgway. There are also 

 specimens from Nevada, California, Utah, Colorado, and Arizona in the collec- 

 tion. Like the balance of the species belonging to this family, Nuttall's Poor-will 

 is crepuscular and nocturnal in its habits, and is rarely met with in the daytime 

 unless accidentally flushed; but as it is very tame, and will scarcely move unless 

 in danger of being stepped on, it is very seldom seen during the day which it 

 spends in repose under some bunch of grass or a low bush, beside a rock or 

 sometimes on one, and although it may often be sitting in plain view and within 

 a few feet of one, it is not readily detected. I think it rarely perches on low 

 limbs of trees. Although common enough in suitable localities throughout its 

 range, genuine eggs of Nuttall's Poor-will are still rare in oological collections. 



Nidification begins rather late; the eaidiest breeding record I have is May 5, 

 from southeastern California; the majority mention the months of June and July, 

 and a sinerle one names the beginning- of August. Two es'firs are laid to a set on 

 alternate days ; I believe both sexes assist in incubation and in the care of the 

 young, and both are devoted parents; they will let you almost touch them before 

 they forsake their treasures. The eggs lay usually on the bare ground, close to 

 some little bush, to shelter them somewhat from the rays of the sun. They vary 

 from oval to blunt elliptical oval in shape; the shell is rather thin, close grained, 

 and moderately glossy. Their color is usually stated to be white, but on close 

 inspection it can readily be seen that it is a delicate cream, with a faint pinkish 

 tint Avhich does not perceptibly fade. Eggs in the collection taken more than 

 twenty years ago still plainly show this peculiar tint. The eggs are unspotted 

 as a rule, but an occasional specimen shows a few faint, darker shell markings 

 around one end, which are barely perceptible to the naked eye, and which fade 

 considerably in time. 



The average measurement of thirteen specimens in the United States 

 National Museum collection is 25.15 by 19.05 millimetres, or 0.99 by 0.75 inch. 

 The largest egg measures 26.67 by 20.32 millimetres, or 1.05 by 0.80 inches; 

 the smallest, 22.35 by 19.30 millimetres, or 0.88 by 0.76 inch. 



The type specimen, No. 24454 (PI. 1, Fig. 23), from a set of two eggs, 

 Ralph collection, was taken in Estes Park, Colorado, on June 19, 1891, and 

 represents about an average-sized specimen of this species. 



