The Black-throated Diver is small and slender. It floats deep in the
water, and when alarmed, swims at surprising speed, with outstretched
neck and rapid beat of the wings, and little more than its head above
the surface.
It flies high and in a direct course with great rapidity.
Mr. Selby describes an ineffectual pursuit of a pair on Loch Shin, in
Sutherlandshire, which was long persevered in. In this case submersion
frequently took place, which continued for nearly two minutes at a time,
and they generally reappeared at nearly a quarter of a mile distant from
the spot at which they went down. In no instance did he ever see them
attempt to escape by taking wing. When swimming, they are in the
constant habit of dipping their bill in the water with a graceful motion
of the head and neck.
“I may observe,” says this acute ornithologist, “that a visible track
from the water to the nest was made by the female, whose progress on
land is effected by shuffling along upon her belly, propelled from
behind by her legs.”
The Black-throated Diver has the beak and throat black; summit of the
head ashy grey; the breast and the sides of the neck white, with black
spots; the back and rump black; the coverts of the wings with white
spots, and all the lower parts pure white. The Bird, though rare in
England and France, is very common in the north of Europe. It is found
on the lakes of Siberia, of Iceland, in Greenland and Hudson’s Bay, and
sometimes in the Orkney Islands. The women of Lapland make bonnets with
its skin dressed without removing the feathers; but in Norway it is
considered an act of impiety to destroy it, as the different cries which
it utters are said to prognosticate fine weather or rain.
The eggs, of which there are two, sometimes three, in the same nest, are
of a very elongated oval form, three inches in length, two inches in the
greatest girth and of a brownish olive sprinkled with black or
dark-brown spots, and are larger at one end than at the other.
In the spring the Sea-birds assemble in large flocks. In fact certain
localities are chosen year after year, and these are occupied by
innumerable flocks at certain seasons, all of which seem to live
together in perfect harmony.
Some of the families of the Swimming Birds are valuable additions to the
poultry yards. Ducks and Geese furnish delicate and nourishing food; the
Swan is gracefully ornamental on our lakes and ponds. The down of all
the aquatic Birds as an article of commerce is of great value in
northern countries. Their eggs constitute good food, and in many
countries the inhabitants consume them in great quantities.
But their usefulness does not end here. Guano, so eagerly sought for by
the farmer, is the excrement of aquatic Fowls which has accumulated for
ages, until in the South Pacific Ocean it is said to have formed whole
islands; some of them being covered with this valuable agricultural
assistant to the depth of ninety or a hundred yards. This does not seem
so marvellous when it is considered that twenty-five or thirty thousand
Sea-birds sleep on these islands night after night, and that each of
them will yield half a pound of guano daily, which owes its unrivalled
fertilizing power to the ammoniacal salts, phosphate of lime, and
fragments of feathers of which it is composed.
Although the numerous Swimming Birds are alike in having webbed feet and
oily plumage that cannot be saturated with water, they have also many
points of difference which make it necessary to divide them into various
families. For instance, some of the Swimmers are feeble and slow in
their flight, and others cannot even rise from the water as their wings
are so small. On the other hand, there are species which possess
wonderful power of traversing the air, their well-developed wings
enabling them to pass through space with marvellous rapidity. The
Petrels seem to delight in storms and tempests, mingling their cries
with the roar of the waves; and the dread which is experienced by the
mariner at the approach of a gale is unknown to the Sea Gull and
Albatros, for they appear to delight in the warring elements.
Because of these differences in their characteristics, Naturalists have
divided the Swimming Birds in various ways, but the best and the
simplest is the division into four great families. First, the Divers, or
the Sea Birds with thin, short wings; second, the large family to which
the Swan and Ducks and Geese belong; third, the Pelican family; fourth,
the Swimming Birds with long wings.