Birds of America
By John James Audubon, F. R. SS. L. & E.
VOLUME VII.
Bird Call
Family
Genus
COMMON TERN.
[Common Tern.]
STERNA HIRUNDO, Linn.
[Sterna hirundo.]
PLATE CCCCXXXIII.--ADULT MALE.
Although the Prince of MUSIGNANO has thought that the bird named the Common
Tern in America, differs from that bearing the same name in Europe, and has in
consequence changed its appellation to that of Wilson's Tern, I am of opinion
that no difference exists between the Common Terns of the two Continents. The
cry of both is besides precisely similar, so that with me there is no doubt
whatever as to their identity. Experience has shewn me that the markings or
white spots on the primary quills of Gulls, at one time assumed as a criterion
by which species might be distinguished, cannot in the least be depended on,
varying, as they always do, in individuals of the same species, at almost each
successive moult. Then why, reader, should not Terns exhibit analogous changes?
The fact is, they do so; and it is almost impossible, on closely inspecting a
dozen or more specimens procured at the same period, in either country, to find
two individuals exactly corresponding in every particular. Some have the bill
almost entirely black, while others have it more or less red and black, and
tipped with yellow. The length of the tail-feathers, that of the tarsus, and
the size of the inter-digital membranes, are all found to differ in some degree,
if minutely compared.
If species are to be founded on such slight differences, an ample field is
open to those who are ambitious of being discoverers. At all events, I cannot
help remarking here, that it seems to me improper to impose new names on
objects, until it is proved by undeniable facts that they present permanent
differences.
I have observed this species along the Atlantic coast of North America,
from Galveston Island in Texas to the Straits of Belle Isle on the coast of
Labrador, both in spring and in early autumn. But when on the islands in
Galveston Bay, in the month of April, I saw only a few arriving there from the
west; whereas, in the beginning of May great numbers arrived there from the
east, settled at once, and commenced breeding. I felt convinced that the
numbers which came from the direction of the Floridas were much greater than
those which arrived from the westward, and judged it probable that vast numbers
had at the same time left the Peninsula on their way northward. Should other
travellers observe the same or similar phenomena at the season mentioned, it
will be proved that this species does not extend its autumnal migration so far
as several others, which I observed arriving at Galveston Island from the
south-west, for example, the Least Tern, Sterna minuta, the Cayenne Tern, St.
cayana, and the Black Tern, St. nigra.
The Common Tern commences breeding on the coast of our Middle Districts
about the 5th of May. On my voyage to Labrador, I found its eggs on the islands
in the Gulf of St. Lawrence, and especially on the Magdalene Islands, which I
visited on the 11th of that month. On the 18th I saw them in great abundance in
the neighbourhood of American Harbour, on the coast of Labrador, where thousands
of Terns were plunging headlong after shrimps all round us. In that country,
their eggs were deposited among the short grass, and the places which they
occupied were but slightly scratched; whereas, on the Magdalene Islands, were
they breed on sandy ridges, slight hollows were scooped out, as is generally the
case along the eastern coast of the United States. Their sojourn in Labrador is
of short duration; and when we were at Newfoundland, on the 14th of August,
multitudes were already passing southward. At the same period considerable
numbers pass by an inland route from the Canadas, and all our great lakes,
travelling along the Ohio and Mississippi. While residing at Henderson, and
afterwards at Cincinnati, I had ample opportunities of watching their movements
in the month of September. And yet, you will think it strange, that, during
their vernal migration, I never saw one ascend any of these rivers or the
streams connected with them. Perhaps the inferior temperature of the waters,
compared with those of the ocean, in the early spring months, may induce them to
abandon their route at that season. In autumn, on the contrary, when these
rivers are heated and reduced in size, the Terns may find in them an abundant
supply of the fry of various fishes. It would thus appear, being corroborated
by other observations which I have made relative to migration, that species
whose range is extensive, are determined in their movements by a genial
temperature and an abundant supply of food.
With an easy and buoyant flight, the Tern visits the whole of our indented
coasts, with the intention of procuring food, or of rearing its young, amidst
all the comforts and enjoyments which kind Nature has provided for it. Full of
agreeable sensations, the mated pair glide along side by side, as gaily as ever
glided bridegroom and bride. The air is warm, the sky of the purest azure, and
in every nook the glittering fry tempts them to satiate their appetite. Here,
dancing in the sunshine, with noisy mirth, the vast congregation spreads over
the sandy shores, where, from immemorial time, the species has taken up its
temporary abode. They all alight, and with minced steps, and tails carefully
raised so as not to be injured by the sand, the different pairs move about,
renew their caresses, and scoop out a little cavity in the soil. If you come
again in a few days, you will find the place covered with eggs. There they lie,
three in each hollow, beautifully spotted and pointed; and as they receive heat
enough from the sun, the birds have left them until evening. But not absent are
they from the cherished spot, for they have seen you, and now they all fly up
screaming. Although unable to drive you away, they seem most anxiously to urge
your departure by every entreaty they can devise; just as you would do, were
your family endangered by some creature as much stronger than yourself as you
are superior to them. Humanity fills your heart, you feel for them as a parent
feels, and you willingly abandon the place. The eggs are soon hatched; the
young in due time follow their parents, who, not considering their pleasant
labour ended when they are able to fly, feed them on wing in the manner of
Swallows, until they are quite capable of procuring their subsistence
themselves. So soon as this is the case, the young birds fly off in bands, to
seek on distant shores, and in sunny climes, the plentiful food which the ocean
yields.
The nest of the Common Tern is, as I have said, a mere hollow made in the
loose sand of some island or mainland beach, scantily tufted with wiry grass, or
strewed with sea-weeds. Their eggs never exceed three in number; their average
length is 1 inch 5 1/2 eighths, their breadth 1 1/4 inches. They vary greatly
in their markings, as is the case with those of all the smaller species of this
family; but their ground colour is generally pale yellowish-green, blotched and
spotted with brownish-black and purplish-grey or neutral tint.
The young, which are fed with small fishes, shrimps, and insects, separate
from the old birds when fully fledged, and do not again associate with them
until the following spring, when both are found breeding in the same places. It
seems quite curious to see these young birds in winter, during boisterous
weather, throwing themselves into the remotest parts of estuaries, and even
visiting salt-water ponds at some distance from the sea, as I have often seen
them do at Charleston, in South Carolina, when accompanied by my friend the Rev.
Dr. BACHMAN. Their plumage is then so very different from that of the old
birds, that one might readily believe them to be of another species, did he not
observe that their mode of flying and their notes are the same. Not less
strange is it, that on such occasions none of the old birds are to be seen in
the place, they having remained, braving the fury of the tempest, on the outer
harbours. In the beginning of winter, young birds also sometimes ascend the
Mississippi as far as Natchez; and in the same manner betake themselves to all
the large lakes bordering the Gulf of Mexico. There, as well as elsewhere, you
see them plunge into the water, and instantaneously secure their prey, rise as
quickly, and dash into another spot hard by, whenever food happens to be
abundant.
I have many times seen the Common Tern suddenly fly up and come close over
a man or a dog, without the least apparent provocation, indeed when far distant
from its nest, and then pass and repass repeatedly within a few yards, emitting
a plaintive cry, as if its eggs or young were in the immediate vicinity. At
other times, when the birds were yet distant from their young, and carrying fish
in their bills, they would, on seeing a man, round to, drop their food, and
perform the same evolutions. I, however, know nothing more remarkable of this
species of Tern, than that it should breed, as I know from personal observation
to be the case, along the whole of our Atlantic coast, in suitable places, from
Texas to Labrador.
When travelling in stormy weather, they skim over the surface of the water,
moving rapidly and close together; whereas in fine weather, they rise high, and
proceed in a straggling manner. Now and then I have seen them alight among
Tringas of different species, as well as among Razor-billed Shearwaters, on
outward sand beaches.
GREAT TERN, Sterna Hirundo, Wils. Amer. Orn., vol. viii. p. 76.
STERNA HIRUNDO, Bonap. Syn., p. 354.
STERNA HIRUNDO, Great Tern, Swains. and Rich. F. Bor. Amer., vol. ii.p. 412.
GREAT or COMMON TERN, Nutt. Man., vol. ii. p. 271.
COMMON TERN, Sterna Hirundo, Aud. Orn. Biog., vol. iv. p. 74.
Male, 16, 31 1/2.
Breeds from Galveston Island along the shores of the Atlantic to Labrador,
and as far north as lat. 57 degrees. Returns southward in autumn, passing
beyond Texas. Extremely abundant.
Adult Male.
Bill about the same length as the head, rather slender, compressed, nearly
straight, tapering to a narrow point. Upper mandible with the dorsal line
slightly arched, the ridge rather broad and convex at the base, narrow towards
the end, the sides sloping, convex towards the end, the edges sharp and
inflected, the tip very slender. Nasal groove rather long, and with a faint
groove and ridge extending obliquely to the edge of the mandible; nostrils
sub-basal, linear, direct, pervious. Lower mandible with the angle very narrow,
extending beyond the middle, the dorsal line straight, the sides ascending and
convex, the edges sharp and inflected, the tip very acute.
Head of moderate size, oblong; neck of moderate length; body very slender.
Feet very small; tibia bare for a considerable space; tarsus very short,
slender, compressed, covered anteriorly with twenty-two small scutella,
laterally and behind with reticular scales; toes very small, slender, the first
extremely small, the third longest, the fourth considerably shorter, the second
shorter than the fourth in the same proportion; the anterior toes connected by
reticulated webs, which are deeply concave at their margin. Claws arched,
compressed, that of the hind toe smallest, of the middle by much the largest,
and having the inner edge thin and dilated.
Plumage soft, close, blended, very short on the fore part of the head; the
feathers, in general, broad and rounded; wings very long, narrow, and pointed;
primary quills tapering to a rounded point, slightly curved inwards, the first
longest, the rest rapidly graduated; secondary quills short, broad, incurved,
obliquely rounded, the inner more tapering. Tail long, very deeply forked, of
twelve feathers, of which the outer are tapering, the middle short and rounded.
Bill bright coral-red, black towards the end, the tip light yellow; inside
of mouth reddish-orange; eye hazel. Feet coral-red, lighter than the bill;
claws brownish-black. Upper part of the head, and the hind neck half-way down,
deep black, the anterior part tinged with brown, the posterior with blue. The
sides of the head, the fore neck, and all the lower parts, white, with a slight
tinge of greyish-blue on the breast. Back, scapulars, and wings, light
greyish-blue, the edges of the wings, the rump, and upper tail-coverts, white,
slightly tinged with grey. First primary with the outer web deep black, the
shaft white, on the inner web a greyish-black band running along the shaft,
narrow at the base, and widening so as to occupy the whole breadth of the web
for an inch at the end, where it is hoary. The next five have the outer web,
and a varying portion of the inner, in nearly their whole length hoary, but at
the same time with a dusky shade, which becomes more apparent at the ends; the
rest of the quills are like the back, but margined and tipped with white.
Tail-feathers with the inner webs white, the outer webs of the colour of the
back, paler on the middle feathers, gradually deepening outwards, and on the
outer feathers dark or blackish-grey.
Length to end of tail 16 inches, to the fork of the tail 11, to end of
wings 15 3/8, to end of claws 11 1/4; extent of wings 31 1/2; wing from flexure
11 3/12; tail to end of lateral feathers 7 1/12, to fork 3 1/12; bare part of
tibia (6 1/2)/12; tarsus (10 1/2)/12; hind toe and claw (3 1/4)/12, middle toe
and claw 1 1/12. Weight 5 oz.
The Female is similar to the male, but rather smaller. In some instances I
have seen a small portion of the forehead white.
Length to end of tail 15 inches, to the fork 11 1/2, to end of wings
15 1/4, to end of claws 11; extent of wings 30 1/4; wing from flexure 10 1/2.
Weight 5 oz.
The Young in their first plumage have the bill dull greenish-black, with
the tip yellowish; the feet greenish-yellow.
In winter, the bill is black, with the base pale orange, and the tip
yellowish; the feet orange-yellow. The colours are as in the adult, the
forehead white, the rest of the head dusky, the upper parts having the feathers
slightly margined with lighter.
Length to end of tail 12 3/4, to the fork 11; to end of wings 14, to end of
claws 10 1/2; extent of wings 29 1/4; wing from flexure 8 1/4.
American and British specimens present no essential differences when
compared in considerable numbers. The outer web of the lateral tail-feather is
blackish-grey, and the inner webs of the tail-feathers are white in all the
specimens collected for comparison. The tarsus in American specimens varies in
length from 9 to 10 1/2 twelfths, and the claw of the middle toe from 2 1/2 to
4 1/2 twelfths; but similar differences are observed in the British birds.
The tongue is 1 4/12 inches long, sagittate and papillate at the base, very
slender, tapering, the point slit, the upper surface a little concave, the lower
horny towards the end. Aperture of posterior nares linear, 9 twelfths long.
Palate with a middle and two lateral ridges. OEsophagus 6 inches long,
extremely wide, its average diameter on the neck 7 twelfths, within the thorax
11 twelfths. The stomach is muscular, 1 inch long, the lateral muscles not
distinguishable, the fasciculi of fibres being disposed as in the rapacious
birds; the central tendinous spaces 3 twelfths in diameter; the cuticular lining
strong, with broad longitudinal rugae. The contents of the stomach, fishes.
The proventriculus 1 inch long. Intestine 1 foot 7 inches long, of moderate
diameter, convoluted, varying from 2 3/4 twelfths to 2 1/2 twelfths. Rectum
1 inch long. Coeca 5 twelfths long, with a diameter of 3/4 of a twelfth.
The trachea is 3 1/4 inches long, 2 1/2 twelfths in breadth above, 1 1/2
twelfths below; its rings 103, feeble and unossified; the lateral muscles
extremely slender; there are sterno-tracheal muscles, but none besides.
Bronchial half-rings about 18.