THE PKAIKiE FALCON. 291 



easy and gracefully accomplished by nlpid wing beats and alternate sailing, 

 and when once launched after the selected victim they are as swift as an 

 arrow. 



I believe that the Prairie Falcon nests almost invariably on rocky cliffs 

 or perpendicular bluffs, on ledges or in small cavities in the same, and but 

 rarely in other situations. Col. N. S. Goss, however, in his "Birds of Kansas," 

 mentions that two eggs of this species now in his brother's collection, were 

 taken April 28, 1880, at Marysville, Missouri, from a tree, the nest being 35 

 feet from the ground ; it was not stated whether the nest was an open one in 

 the forks of branches, or in a hole of the tree, but doubtless the latter. Mr. 

 Walter E. Bryant, of San Francisco, California, who has taken a number of 

 sets of eggs of this species, found them invariably on cliffs from 30 to 1 00 feet 

 from the bottom. A handsome set of five eggs, which he kindly presented 

 to the writer, was taken on March 25, 1*82, at Pine Canon, near Mount 

 Diablo, California, and were fresh when found; they were laid in a cavity 

 of a cliff about 4 feet in depth on some sand and bits of fur, feathers, etc., 

 ejected by the birds, there being 110 nest. The cliff was about 100 feet high 

 iind perpendicular, and the site about 30 feet from its base. 



Sets of eggs of the Prairie Falcon now in the U. S. National Museum 

 collection, from near Gilmer, and others from the Wind River Mountains, 

 Wyoming, as well ag from Battle Mountain, Nevada, were all taken in sim- 

 ilar situations. The first eggs of this species brought to the attention of 

 naturalists were a set of three taken on Gros Ventre River, in the Wind 

 River Mountains, by Dr. F. V. Hayden, on June 8, 1860. 



Mr. Walter E. Bryant also found a pair of these Falcons nesting in a 

 high cliff near San Esteban, Lower California, on April 18, 1889. The 

 earliest date on which he took full sets of eggs of this species in California 

 was March 24, 1881, and fresh eggs were taken by him as late as April 7. 

 These dates are probably as early as they nest anywhere within their 

 range. Farther north nidification is protracted through April and the begin- 

 ning of May, and occasionally even into the first week in June. As a rule 

 there is but little of a nest, if any, the eggs being usually laid on the bare 

 rock, among some of the refuse carried there as food, such as bones, bits 

 of fur, and feathers. 



The eggs number from three to five, sets of five seeming to be the 

 usual number found on the Pacific coast, while in the interior sets of three 

 or four are perhaps more common. Occasionally but two eggs have been 

 found, but it is doubtful if such so-called sets were complete when taken. 

 Should they lose their first clutch of eggs a second and smaller one is 

 sometimes laid. The eggs are deposited at intervals of a day or two, and 

 nidification lasts probably from three to four weeks. The young when first 

 hatched are covered with a thick white fluffy down, and they grow rapidly. 

 As soon as they are fully grown and able to care for themselves they are 

 turned adrift to make their own living, and fall easy victims to the guns 



