(_Alca torda_)
The razorbill, or auk, which, in suitable localities, is one of the
commonest of British sea-birds, has an interest all its own from the
circumstance that it is the nearest living relative of the now extinct
great auk, these two species being, in fact, the sole members of the
genus _Alca_. Both these birds present a considerable superficial
resemblance to the penguins of the Southern Hemisphere; and it seems to
be due to this resemblance that the latter owe their name, for there
appears to be little doubt that the great auk was the true and original
penguin, or pinguin, and that the birds we now know by that name were
so called by the old voyagers on account of their likeness to the
former species. Such resemblance as exists between the two groups is,
however, merely of the most superficial kind, auks being strong fliers,
with feet of normal structure, whereas the wings of penguins serve the
purpose of paddles, and the bones of their feet are quite unlike those
of all other birds.
Auks, in fact, appear to be near relatives of the gulls and terns,
which have assumed, in accordance with their mode of life, a partially
upright position of body. For these birds, in common with guillemots,
very frequently breed on the narrow ledges of cliffs, where it is
obvious that an upright posture affords them greater facilities for
movement and at the same time economises space. In accordance with this
habit, razorbills, in common with other members of the auk tribe, lay
pear-shaped eggs, which cannot well roll off the bare ledges of rock
on which they are often laid. As a rule, each female deposits only
one, relatively large, egg; while no female incubates more than a pair
of these eggs at the same time. Sometimes, in place of a bare ledge,
the egg is laid in a hollow in the rock, or, where the soil is of a
suitable nature, in a hole excavated by the parent bird.
All members of the auk tribe are inhabitants of the cooler portions
of the Northern Hemisphere; their place in the corresponding southern
latitudes being taken by the aforesaid penguins.
[Illustration]
In addition to its remarkable bodily shape, the adult razorbill is
easily recognised by the great lateral compression and subterminal
expansion of the beak, from which the bird derives its ordinary
vernacular name; as well as by the deep groovings and wide band on the
sides of this appendage. The curved white stripe running from just
in front of the eye to the root of the beak is another distinctive
feature of the species; and this, too, in a more or less distinct
form, in birds of all ages, whereas in the young the groovings and
white markings on the beak are wanting. Considerable difference exists
between the summer and winter plumages of the adult birds. In summer
the head and neck are sooty brown, while the back and wings are black
with a greenish gloss; the beak and the rest of the under-parts,
together with a narrow wing-bar, being white. On the other hand, the
winter plumage of the adults, like that of the young in summer, is
browner above, while the sides of the head and the fore portion of the
neck are of the same snowy white as the under-parts of the body.
The razorbill inhabits the coasts on both sides of the North Atlantic,
breeding far up on the Norwegian coast, on those of Iceland and the
Faröe Islands, and on the opposite side of the ocean on the shores of
Newfoundland, Labrador, and Greenland; latitude 70° about marking its
northward breeding range on the American side, while in Europe the
limit is about one degree less. Eastwards the range extends to Jan
Mayen Island; while the southward boundary of the breeding area in
Europe appears to be formed by the Brittany coasts. In great Britain
these birds breed, in suitable localities, all round the coasts,
inclusive of those of the Shetland Islands. These limits do not,
however, by any means indicate the whole range of the species, for
in winter these birds visit the Mediterranean, and occasionally the
Canaries.
Throughout the year razorbills associate in large flocks, although in
autumn the numbers of these colonies are diminished, apparently by a
portion of the birds going out to sea. Bempton Cliffs, on the Yorkshire
coast, form one of their favourite breeding-places, where the birds
congregate in thousands, in company with guillemots, and yield a large
harvest of eggs. The laying season commences about the middle of May,
but is at its height some days later; while eggs and young may be found
together till late in June. By the end of July the birds have for the
most part finished their breeding season, and by the first week in
August nearly all have forsaken the cliffs for the sea, which is their
true home, and on which they often pass the night.