12 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



once their folly in coming so near and screaming so loudly over our heads attracted 

 attention to some that would otherwise have escaped notice. The earliest date 

 of finding a nest was May 10, 1863, at Anderson River Fort. The eggs, three in 

 number, were quite fresh. In another, taken five days later, the eggs contained 

 partially formed embryos. In a few cases young birds were found in the same 

 nest with eggs, the contents of which were but little changed, and in another nest 

 a perfectly fresh egg was found with several ready to hatch. In nearly every case 

 the eggs seemed to be in different stages of development, and incubation seems to 

 begin as soon as the first egg is laid. 



Eggs. — I cannot do better than to quote Bendire's (1892) descrip- 

 tion of the eggs, which will apply equally well to all the gyrfalcons, as 

 follows: 



The eggs are three or four in number. The ground color, when distinctly 

 visible, which is not often the case, is creamy white. This is usually hidden by a 

 pale cinnamon rufous suffusion. In an occasional specimen it seems to be pinkish 

 vinaceous. The eggs are closely spotted and blotched with small, irregular mark- 

 ings of dark reddish brown, brick-red, ochraceous rufous, and tawny. These 

 markings — usually pretty evenly distributed over the entire egg — are generally 

 small in size, and more or less confluent. Some specimens show scarcely any trace 

 of markings, the egg being of nearly uniform color throughout. * * * In the 

 general pattern of markings the eggs of the Gyrfalcon approach those of the 

 Prairie Falcon (Falco mexicanus) much closer than those of the Duck Hawk (Falco 

 peregrinus anatum), which as a rule are much darker. In shape they vary from 

 ovate to rounded ovate. The shells of these eggs feel rough to the touch, are ir- 

 regularly granulated, and without luster. 



The measurements of 55 eggs average 59.4 by 45.3 millimeters; the 

 eggs showing the four extremes measure 63 by 46.5, 61 by 48, 56 by 

 46.2, and 61 by 42 millimeters. 



Young. — Mr. Turner says in his notes: "The young birds are able 

 to leave the nest by the middle of August, and in September of some 

 years they are quite abundant, flying over the houses at Fort Chimo 

 with but little fear. They generally evince but little disposition to 

 show fierceness, and on only two occasions did they display more than 

 ordinary courage. They will not seize with the beak when wounded, 

 but will grasp firmly with the claws. They immediately lie on their 

 backs when wounded." 



Plumages.- — So far as I know, there are no specimens of the small 

 downy young of this gyrfalcon in any American collection. Witherby's 

 Handbook (1924) describes a very young specimen of rusticolus as 

 follows: "Down white with a slight creamy tinge, rather short, cover- 

 ing bird well on upper parts, but thinly on sides of belly and bare patch 

 at base of sides of neck." 



A small nestling of the Iceland bird, in the Museum of Compara- 

 tive Zoology, is about half grown but still largely downy; the "clove 

 brown" juvenal plumage is growing on the crown, scapulars, wings, 

 tail, and sides of the breast; otherwise it is thickly covered with long, 

 soft, woolly down, white to buffy white in color. 



