Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/771

Rh NEARCTIC REGION.] BIRDS 753 peculiarly Nearctic, though, of the species 58 are truly American against 52 common to both Regions, one of these last, however, not having been found elsewhere in the New World, while the home of 5 seems doubtful. These numbers will show the great influence of Palsearctic forms on Alaska, and it only remains to be said that some of the ordinary summer-migrants thither would seem to arrive there from Asia, as the Wagtail and Willow- Wren just mentioned, to which should possibly be added the Wheatear (Saxicola cenantJie), for though that species is known as a regular annual visitant to Greenland and Labrador (where it breeds), and almost annually appears as a straggler on the eastern coast of the United States, the flocks which throng the stony hill-tops of Alaska in spring are not likely to have performed a north-west passage from Europe, and indeed it is stated that specimens from Norton Sound differ considerably in dimensions from those obtained in Green land. All these Birds are unseen in British Columbia, and as all are migratory, the inference that they make some part of Asia their winter-quarters is almost irresistible. After all, perhaps there is nothing very surprising in this, when we consider the narrowness of the channel 1 by which in these longitudes the New World is divided from the Old, and it would seem that it is almost within the confines of the Arctic circle that, apart from circumpolar species, the connection of the faunas of the two continents is closest. in At any rate, the Aleutian Islands, though they look like v ~ stepping-stones from the one to the other, do not appeal to be used as a route of communication ; for Mr Dall calls especial attention to the fact that no intrusion of Asiatic forms occurs towards the western end of the chain, while observing that its avifauna beyond Oonalaska is reinforced by several Arctic species not possessed by more eastern islands. 2 Northward of the Aleutians lies a little volcanic group known as the Prybilov Islands, whose coasts are frequently encumbered by ice, and there only 40 species of Birds have as yet been found, while those which breed are about 12 in number, and among them a Sandpiper (Tringa ptilocnemis), apparently peculiar to St Paul s Island, the largest of the group. Only one of the characteristically Pakearctic forms, and this also a Water-bird (Limosa iiropygialis), which appear but in Alaska, seems there to occur a fact which points yet again to the more northern connection of the two continents by way of Cape Prince-of- Wales and the East Cape (Vostochni) of Asia. ilas. We have next to turn to another group of islands, situated in a different ocean, and in formation very unlike that last considered. These are the Bermudas, a cluster of low coral-reefs rising from the Atlantic, about 600 miles from Cape Hatteras, the nearest point on the eastern coast of North America. They possess but few Land-birds, and not a single peculiar species, yet they play by no means an unimportant part as a resting-station to the flocks of migrants as they retreat southward from their northern homes in Labrador and Greenland, and, though less often, on their northward journey in spring. Only about 6 Land- birds are resident, and about as many Water-birds are known to breed there ; but the number of stragglers is large, and includes two or three of undoubtedly European extraction.
 * ind Greenland is the last portion of the Nearctic Region to

which we shall especially invite attention, and there though the character of the avifauna is certainly that of the New World, yet that of the Old is very influential. Out of the 45 genera to which the feathered inhabitants of Greenland 1 Behring s Strait is said also to be very shallow, which fact is sug gestive as to a still greater interchange of animal life in past ages. 2 Proceedings of the Calif omian Academy of Sciences, 14th March 1S74, Similarii of Nearc f auna. belong, none are peculiar to the Pal?earctic Eegion, while 2 Zonotrichia, one of the Emberizidce, and Rhodostethia, one of the Laridce are peculiar to the Nearctic. If we take the species, we find that of the G3 inhabitants, those peculiar to the New World amount to 11, while those not elsewhere dwelling out of the Old are only 5. &amp;lt; But, on the other hand, the Sea-Eagle (Haliaetus), the Ringed Plover (jEgia- litis), and the Snipe (Scolopax) which breed in Greenland are those of Europe instead of their American congeners ; and the Wheatear (Saxicola}, the Sanderling (Calidris), the Knot (Tringa canutus), and the Bernacle-Goose (Bernicla leucopsis) would appear to cross the Atlantic from the east, while 43 out of the 63 inhabitant species are every bit as much Palaearctic as Nearctic ; and 2 more, the Ptar migan (Lagopus rupestris) and Barrow s Duck (Clangula islandica) breed abundantly in Iceland. Following the western coast-line (for of the eastern we know little) to the Arctic circle, 3 we find the proportion of forms which are common to the Palsearctic Region increase, until in lat._75 N. or thereabouts, there are (so far as our means of infor mation will allow us to judge) no species of Birds which have not been known to occur, and only about 5 which have not been known to breed, in the Old World. It has been already stated that 128 out of the 330 Nearctic genera, or more than one-third, are common also to the Palsearctic Region. This will serve to shew the great similarity of the two ; and if we investigate the species, the similarity is still to a great extent borne out. Taking the number of Nearctic species at 700 (which is perhaps an exaggeration), and that of the Palsearctic at 850 (which is certainly under the mark), we find that, exclusive of stragglers, there are about 100 common to the two Regions. Nearly 20 more are Palaearctic but occasionally occur in America, and about 50 are Nearctic which from time to time stray to Europe or Asia. 4 But this is not the only ground of the resemblance. Of many genera the species found in the New World are represented in the Old by species which often no one but an expert can distinguish. Of such representative or parallel species, somewhere about 80 might be enumerated ; and thus the relation of the two regions may be concisely stated : Species inhabiting the Nearctic Eegion ____ Species of one Ee gion represented by closely allied forms in the other ......... Palaearctic species oc casionally found in the Nearctic Eegion IV. THE PAL^EARCTIC REGION begins with the Atlantic PAL.E- Islands (the Azores, Canaries, and Madeiras) and includes ARCTIC that portion of North-west Africa which was formerly ^ EGIOX known as the Barbary States, the whole of Europe and its Bound- islands from Iceland and Spitsbergen to those of the aries. Mediterranean Asia Minor, Palestine, Persia, Afghanistan. and all the rest of the Asiatic continent lying to the north ward of the Himalaya Mountains and of a line drawn as though it was a prolongation of that range to the east- 3 People are apt to forget that Cape Farewell, the most southerly point of Greenland, lies in the latitude which cuts the Shetlands and passes far to the south of Iceland ; and a large portion of the country though undoubtedly exposed in the highest degree to the rigours of an Arctic climate, is situated outside the Arctic circle. 4 Professor Baird, in the essay.before cited, has reasonably accounted for this disproportionate reciprocity between Europe and America; but perhaps something more than he has allowed must be set down to the comparative want of records in the new country, where observers and amateur collectors have until lately been scarce. This want is, however, being speedily supplied by the numerous students of out-of- doors ornithology, who are everywhere springing up throughout the United States. III. - 95 (say) 700. (say) 80. Species inhabiting the Palaearctic Eegion.. Species identical in both Eegions (say) 850. (say) 100. (say) 20. Nearctic species occa sionally found in the Palsearctia Eegion.. (say) 50,