AVES. 315 



Tlie Snow Owl is often seen in Norway and Sweden, but is of rare 

 occurrence in France or the Britisli Islands. In Ireland it ajipears to l)o 

 of more frequent occurrence than in Creat Britain. 



Audubon mentions that a specimen in captivity fed upon small fishes or 

 pieces of fish placed in water, and Wilson also mentions havini^ seen this 

 bird engaged in fishing. Its usual food is said, however, to be the northern 

 hares, grouse, ducks, mice, and even carrion, which it feeds upon by day- 

 light as well as in the twilight of the evening. It breeds in the far north, 

 and is said to make its nest upon the ground, and to lay three or four 

 white eggs. 



The Hawk Owl is another northern species, though not inhabiting 

 regions so far north as the preceding, nor does it proceed so far south in 

 its winter migrations, being very rarely found in the latitude of Phila- 

 delphia. Wilson's description of this curious bird is, as usual, much to the 

 purpose: "This is an inhabitant of both continents, a kind of etiuivocal 

 species, or rather a connecting link between the hawk and owl tribes, 

 resembling the latter in the I'eet and in the radiating feathers around the 

 eye and bill, but apj)roaching nearer to the former in the smallness of its 

 head, narrowness of its face, and in its length of tail. In short, it seems 

 just such a figure as one would expect to see generated between a hawk 

 and an owl of the same size, were it possible for them to produce, and yet 

 is as distinct, independent, and original a species as any other. It has also 

 another strong trait of the hawk tribe, in flying and ))reying by day, con- 

 trary to the general habit of owls. It is characterized as a bold and active 

 species, following the fowler and carrying off his game as soon as it is shot. 

 It is said to prey on partridges and other birds, and is very comn)on at 

 Hudson's Bay. We are also informed that this same species inhabits 

 Denmark and Sweden, is frequent in all Siberia, and on the west side 

 of the Uralian chain as far as the Volga. This species is very rare in 

 Pennsylvania and the more southern parts of the United States. Its 

 favorite range seems to be along the borders of the Arctic regions, making 

 occasional excursions southwardly, when compelled by severity of weather 

 and consequent scarcity of i'ood. I some time ago received a drawing of 

 this bird from Maine ; that and another specimen which was shot in the 

 neighborhood of Philadelphia are the only two that have come under mv 

 notice. Of their nest or manner of breeding we have no account." 



With this sub-family we conclude the Rapacious Birds. 



Order II. Passeres. 



This order contains more binls than all the other orders together. It 

 comprises all the birds which imve feet especially formed for perching and 

 a general organization enabling them to live amongst trees, in which a 

 large majority of the species habitually pass their lives. 



The claws are weak and not retractile as in the Accipitkes, and the 

 hind toe is not only upon the same plane, but is as nnich capable of grasp- 



519 



