.262 LIFE HISTORIES OF NORTH AMERICAN BIRDS. 



This species has also been found breeding in northern Utah by Mr. C. S. 

 McCarthy, while attached as naturalist to Capt. J. H. Simpson's exploring 

 expedition, and the parents as well as the eggs are now in the U. S. National 

 Museum collection. The nest was found in Rush Valley, on May 3, 1859, 

 and was placed in a cedar tree 15 feet from the ground ; it contained four eggs. 



The first eggs of the Ferruginous Rough-leg brought to scientific notice 

 are a set of four, taken by Capt. T. Blakiston, on April 30, 1858, and one 

 of these is figured. The nest was placed in an aspen tree 20 feet from the 

 ground, and was composed of sticks, lined with buffalo wool. It was a large, 

 bulky affair, measuring 2£ feet across. It was found between the north and 

 south branches of the Saskatchewan River, Manitoba. Another set of egg's, 

 taken in the same locality, five in number, came from a nest only 10 feet 

 from the ground. None of the eggs of this set are in the U. S. National 

 Museum collection. 



Probably but one brood is raised in a season; the eggs, from two to five 

 in number, usually three or four, are deposited about April 15 in the more 

 southern portions of its range, and from two to four weeks later farther north- 

 ward. Nesting sites seem to be as often selected on the ground as in trees, 

 and if in the latter they are frequently quite near the ground. Incubation, 

 as with most of the large Hawks, probably lasts about four weeks. The eggs 

 are laid at intervals of two or three days. They are large and among the 

 handsomest of those of the Raptores, and in shape usually ovate, seldom 

 elliptical ovate. The shell is close grained and compact, dull creamy or pale 

 greenish white in color, irregularly blotched and spotted with various shades 

 of brown, and a few pale lilac and lavender shell markings. In some spec- 

 imens the darker markings predominate, and in others the reverse is the case. 

 An occasional egg is almost unmarked, and the larger sets usually contain 

 one or two eggs much less marked than the others, and sometimes almost 

 entirely unspotted. 



The average measurement of fifteen specimens in the U. S. National 

 Museum collection is 63.5 by 49 millimetres. The largest egg of the series 

 measures 66 by 50.5, the smallest 61 by 48 millimetres. 



Of the type specimens, No. 2662 (PL 9, Fig. 2), selected from a set of four, 

 was collected by Capt. T. Blakiston, April 30, 1858, on the Saskatchewan 

 plains, British North America; the other two eggs, both from the same set, No. 

 22717 (PL 9, Figs. 1 and 4), were collected by Capt. B. F. Gross in the Coteau 

 Hills, North Dakota, May 12, 1880, and obtained in exchange. They show 

 the different styles of coloration often found in eggs of the same set. 



