AVES. 315 
The Snow Owl is often seen in Norway and Sweden, but is of rare 
occurrence in France or the British Islands. In Ireland it appears to be 
of more frequent occurrence than in Great Britain. 
Audubon mentions that a specimen in captivity fed upon small fishes or 
pieces of fish placed in water, and Wilson also mentions baving 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 equivocal 
species, or rather a connecting link between the hawk and owl tribes, 
resembling the latter in the feet and in the radiating feathers around the 
eye and bill, but approaching 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 preying 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 common 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 food. 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 my 
notice. Of their nest or manner of breeding we have no account.” 
With this sub-family we conclude the Rapacious Birds. 
Orper Il. Passergs. 
This order contains more birds than all the other orders together. It 
comprises all the birds which have 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 Accrprrres, and the 
hind toe is not only upon the same plane, but is as much capable of grasp- 
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