or of the minute organisms which abound in the blown sand.[[107]]
Zoology of Bermuda.—As might be expected from their extreme isolation, these islands possess no indigenous terrestrial mammalia, frogs, or snakes.[[108]] There is however one lizard, which Professor Cope considers to be distinct from any American species, and which he has named Plestiodon (Eumeces) longirostris. It is said to be most nearly allied to Eumeces quinquelineatus of the south-eastern States, from which it differs in having nearly ten more rows of scales, the tail thicker, and the muzzle longer. In colour it is ashy brown above, greenish blue beneath, with a white line black-margined on the sides, and it seems to be tolerably abundant in the islands. This lizard is especially interesting as being the only vertebrate animal which exhibits any peculiarity.
Birds.—Notwithstanding its small size, low altitude and
remote position, a great number of birds visit Bermuda annually, some in large numbers, others only as accidental stragglers. Altogether, over 180 species have been recorded, rather more than half being wading and swimming birds, whose presence is not so much to be wondered at as they are great wanderers; while about eighty-five are land birds, many of which would hardly be supposed capable of flying so great a distance. Of the 180 species, however, about thirty have only been seen once, and a great many more are very rare; but about twenty species of land birds are recorded as tolerably frequent visitors, and nearly half these appear to come every year.
There are only eleven species which are permanent residents on the island—eight land, and three water birds, and of these one has been almost certainly introduced. These resident birds are as follows:—
1. Galeoscoptes carolinensis. (The Cat bird.) Migrates along the east coast of the United States.
2. Sialia sialis. (The Blue bird.) Migrates along the east coast.
3. Vireo novæboracensis. (The White-eyed green Tit.) Migrates along the east coast.
4. Passer domesticus. (The English Sparrow.) ? Introduced.
5. Corvus americanus. (The American Crow.) Common over all North America.
6. Cardinalis virginianus. (The Cardinal bird.) Migrates from Carolina southward.
7. Chamœpelia passerina. (The ground Dove.) Louisiana, W. Indies, and Mexico.
8. Ortyx virginianus. (The American Quail.) New England to Florida.
9. Ardea herodias. (The Great Blue Heron.) All North America.
10. Gailinula galeata. (The Florida Gallinule.) Temperate and tropical North America.
11. Phäeton flavirostris. (The Tropic Bird.)
It will be seen that these are all very common North American birds, and most of them are constant visitors from the mainland, so that however long they may have inhabited the islands there has been no chance for them to have acquired any distinctive characters owing to the want of isolation.
Among the most regular visitants which are not resident, are the common N. American kingfisher (Ceryle alcyon),
the night-hawk (Chordeiles virginianus), the wood wagtail (Siurus novæboracensis), the snow-bunting (Plectrophanes nivalis), and the wide-ranging rice-bird (Dolichonyx oryzivora), all very common and widespread in North America.
Comparison of the Bird-faunas of Bermuda and the Azores.—The bird-fauna of Bermuda thus differs from that of the Azores, in the much smaller number of resident species, and the presence of several regular migrants. This is due, first, to the small area and little varied surface of these islands, as well as to their limited flora and small supply of insects not affording conditions suitable for the residence of many species all the year round; and, secondly, to the peculiarity of the climate of North America, which causes a much larger number of its birds to be migratory than in Europe. The Northern United States and Canada, with a sunny climate, luxuriant vegetation, and abundant insect-life during the summer, supply food and shelter to an immense number of insectivorous and frugivorous birds; so that during the breeding season Canada is actually richer in bird-life than Florida. But as the severe winter comes on all these are obliged to migrate southward, some to Carolina, Georgia, and Florida, others as far as the West Indies, Mexico, or even to Guatemala and South America.