(SPOT-WINGED GULL.)
+Larus maculipennis+, _Scl. et Salv. Nomencl._ p. 148; _Durnford,
Ibis_, 1877, p. 202 (Buenos Ayres), et 1878, p. 405 (Centr.
Patagonia); _White, P. Z. S._ 1882, p. 628 (Buenos Ayres);
_Saunders, P. Z. S._ 1878, p. 201; _Withington, Ibis_, 1888, p.
472 (Lomas de Zamora). +Larus serranus+, _Burm. La-Plata Reise_,
ii. p. 519. +Larus cirrhocephalus+, _Scl. et Salv. P. Z. S._
1868, p. 146 (Buenos Ayres); _Hudson, P. Z. S._ 1871, p. 4.
_Description._--Head and nape brownish-black (in breeding-dress);
tail and underparts white; mantle pale grey; primaries black or dark
grey, tipped with white, and with large elongated white patches on
the outer portions of first to fifth, followed by a subapical _black
bar_ (in _L. glaucodes_ the lower portion is _white_): underwing
_pale grey_; bill, legs, and feet blood-red: length 16·0-17·0
inches, wing 11·5.
[Illustration: Three outer primaries of adult SPOT-WINGED GULL.
(P. Z. S. 1878, p. 202.)]
_Hab._ Southern Brazil, Uruguay, and La Plata.
This common Black-hooded Gull is found throughout the Argentine country,
down to Chupat in Patagonia, and is exceedingly abundant on the pampas
of Buenos Ayres, where it is simply called _Gaviota_. In the month of
October they congregate in their breeding-places--extensive inland
marshes, partially overgrown with rushes. The nests are formed of weeds
and rushes, placed just above the water and near together, several
hundreds being sometimes found within an area of less than one quarter
of an acre. The eggs are four in number, large for the bird, obtusely
pointed, of a pale clay-colour, thickly spotted at the big end and
sparsely on the other parts with black.
Every morning, at break of day, the Gulls rise up from their nests and
hover in a cloud over the marsh, producing so great a noise with their
mingled cries that it can be heard distinctly at a distance of two
miles. The eggs are considered a great delicacy, resembling those of
the Plover in taste and appearance, and are consequently much sought
after, so that when the locality near which a gullery is situated
becomes inhabited the birds have no chance of rearing their young, as
the boys in the neighbourhood ride into the marsh every morning to
gather the eggs. The Gulls are, however, very tenacious of their old
breeding-places, and continue even after years of persecution to resort
to them.
The young birds are of a pale grey colour, mottled with dull brown, and
have a whining querulous cry. The plumage becomes lighter through the
autumn and winter, but it is not until the ensuing summer, when the dark
brown nuptial hood is assumed, that the young birds acquire the perfect
plumage--soft grey-blue above, and the white bosom with its lovely pink
blush.
As soon as the young are able to fly the breeding-place is forsaken, the
whole concourse leaving in a body, or scattering in all directions over
the surrounding country; and until the following summer their movements
depend entirely on food and water. If the weather is dry the Gulls
disappear altogether; and if grasshoppers become abundant the country
people wish for rain to bring the Gulls. When it rains then the birds
quickly appear, literally from the clouds, and often in such numbers as
to free the earth from the plague of devastating insects. It is a fine
and welcome sight to see a white cloud of birds settle on the afflicted
district; and at such times their mode of proceeding is so regular that
the flock well deserves the appellation of an army. They sweep down with
a swift graceful flight and settle on the earth with loud joyful cries,
but do not abandon the order of attack when the work of devouring has
begun. The flock often presents a front of over a thousand feet, with
a depth of sixty or seventy feet; all along this line of battle the
excited cries of the birds produce a loud continuous noise; all the
birds are incessantly on the move, some skimming along the surface with
expanded wings, others pursuing the fugitives through the air, while
all the time the hindmost birds are flying over the flock to alight in
the front ranks, so that the whole body is steadily advancing, devouring
the grasshoppers as it proceeds. When they first arrive they seem
ravenously hungry, and after gorging themselves they fly to the water,
where after drinking they cast up their food and then go back to renew
the battle.
In spring these Gulls come about the farms to follow the plough, filling
the new-made furrows from end to end, hovering in a cloud over the
ploughman's head and following at his heels, a screaming, fighting
crowd. When feeding they invariably keep up a great noise. Wilson's
expression in describing a northern species, that its cry "is like the
excessive laugh of a negro," is also descriptive of the language of
our bird. Its peculiar cry is lengthened at will and inflected a
thousand ways, and interspersed with numerous short notes, like excited
exclamations. After feeding they always fly to the nearest water to
drink and bathe their feathers, after which they retire to some open
spot in the neighbourhood where there is a carpet of short grass. They
invariably sit close together with their bills toward the wind, and
the observer will watch the flock in vain to see one bird out of this
beautiful order. They do not stand up to fly, but rise directly from a
sitting posture. Usually the wings are flapped twice or thrice before
the body is raised from the ground.
In some seasons in August and September, after a period of warm wet
weather, the larvæ of the large horned beetle rise to the surface,
throwing up little mounds of earth as moles do; often they are so
numerous as to give the plains, where the grass has been very closely
cropped, the appearance of being covered with mud. These insects afford
a rich harvest to the Spur-winged Lapwing (_Vanellus cayennensis_),
which in such seasons of plenty are to be seen all day diligently
running about, probing and dislodging them from beneath the fresh
hillocks. The Gulls, unprovided with a probing beak, avail themselves
of their superior cunning and violence to rob the Lapwings; and I have
often watched their proceedings for hours with the greatest interest.
Hundreds of Lapwings are perhaps visible running busily about on all
sides; near each one a Gull is quietly stationed, watching the movements
of its intended dupe with the closest attention. The instant a great
snow-white grub is extracted the Gull makes a rush to seize it, the
Lapwing flies, and a violent chase ensues. After a hundred vain
doublings the Plover drops the prize, and slopes toward the earth with
a disappointed cry; the pursuer checks his flight, hovers a moment
watching the grub fall, then drops down upon it, gobbles it up, and
hastens after the Lapwing to resume his watch.
Many of these Gulls haunt the estancias to feed on the garbage usually
found in abundance about cattle-breeding establishments. When a cow is
slaughtered they collect in large numbers and quarrel with the domestic
poultry over the offal. They are also faithful attendants at the
shepherd's hut; and if a dead lamb remains in the fold when the flock
goes to pasture they regale on it in company with the Chimango. The
great _Saladeros_, or slaughter-grounds, which were formerly close to
Buenos Ayres, are also frequented by hosts of these neat and beautiful
scavengers. Here numbers may be seen hovering overhead, and mingling
their excited screams with the bellowing of half-wild cattle and the
shouts of the slaughterers at their rough work; and at intervals,
wherever a little space is allowed them, dropping themselves on to the
ground, which reeks with blood and offal, and greedily snatching up
whatever morsels they can on the instant, and yet getting no stain or
speck on their delicate dress of lily-white and ethereal blue.
On the open pampas their curiosity and anger seems greatly excited at
the appearance of a person on foot; no sooner has the Gull spied him
than it sweeps toward him with a rapid flight, uttering loud indignant
screams that never fail to attract all of its fellows within hearing
distance. These all pass and repass, hovering over the pedestrian's
head, screaming all the time as if highly incensed, and finally retire,
joining their voices in a kind of chorus and waving their wings upwards
in a slow curious manner; but often enough, when they are almost out of
sight, they suddenly wheel about and hurry back screaming, with fresh
zeal, to go through the whole pretty but annoying performance again.