(YELLOW HOUSE-SPARROW.)
+Sycalis pelzelni+, _Scl. Ibis_, 1872, p. 42; _Scl. et Salv.
Nomencl._ p. 34; _Durnford, Ibis_, 1877, p. 172 (Buenos Ayres).
_Description._--Above yellowish olive-green, the back sparsely
striped with blackish; wing- and tail-feathers black, edged with
yellow; forehead bright orange, the rest of the head like the back;
below bright yellow; under surfaces of wings and tail also yellow:
total length 5·4 inches, wing 2·7, tail 2·2. _Female_ dull brownish
grey mottled with blackish above; under surface whitish grey,
striped with dusky brown on the breast; wing- and tail-feathers
edged with yellow.
_Hab._ S. Brazil, Paraguay, and Argentina.
The Yellow "House-Sparrow," as this species is called, is the town-bird
of Buenos Ayres, but does not multiply greatly, nor is he familiar with
man, like his rough, sooty-plumaged, far-away London relation.
The forehead of the male is bright orange, the prevailing colour of the
entire plumage yellow, clouded with other hues. The female is grey,
marked with pale fuscous, and is less in size than her mate. They remain
with us all the year and live in pairs, the sexes in this species being
faithful. Sometimes they are seen associating in small flocks, but I am
inclined to believe that only the young unmated birds are gregarious. In
1867-8, during the cholera epidemic in Buenos Ayres, the Sparrows all
disappeared from the town, and I was told by the manager of a large
steam flour-mill in the town that the birds had not gone away, but had
died. They were found dead all about the mill where they had been very
abundant. My informant was a careful observer, and I have no doubt that
he was correct in what he told me.
In spring and summer the male sings frequently with great energy, but
without much melody. After a hurried prelude of sharp chirps and trills,
he pours out a continuous stream of sound, composed of innumerable brief
notes, high and shrill as those of a bat, wounding the ear with their
excessive sharpness, and emitted so rapidly that the whole song is more
like that of a cicada than of a bird. This piercing torrent of sound is
broken at intervals by a long grave note, or half a dozen short rapid
notes in a lower key, which come as an agreeable relief.
In towns they build in walls, like the English Sparrow; in country
places they always select the domed nest of some Dendrocolaptine species
to breed in. Possibly in some districts where I have not been, this
Sparrow selects other breeding-sites; my experience is that outside of
a town it never lays anywhere but in some domed nest, and at home I
frequently put up boxes for them in the trees, but they would not notice
them, though the Wrens and Swallows were glad to have them. Sometimes
they make choice of the large fabric of the _Anumbius acuticaudatus_,
called Leñatero in the vernacular; but their claim to this nest (even
when the Leñateros are out of it) is frequently disputed by other
species which possess the same habit as this Sparrow, but are more
powerful than he. Their favourite breeding-place is, however, the solid
earthen structure of the Oven-bird; and it is wonderful to see how
persistently and systematically they labour to drive out the lawful
owners--birds so much larger and more powerful than themselves. Early in
spring, and before the advent of the Tree-Martins, the pair of Sparrows
begin haunting the neighbourhood of the oven they have elected to take
possession of, usually one pretty high up in a tree. As the season
advances their desire towards it increases, and they take up their
position on the very tree it is in; and finally a particular branch
near the oven, commanding a good view of the entrance, is chosen for a
permanent resting-place. Here they spend a great portion of their
time in song, twitterings, and loving dalliance, and, if attentively
observed, they are seen with eyes ever fixed on the coveted abode. As
the need for a receptacle for the eggs becomes more urgent they grow
bolder, and in the absence of the owners flit about the oven, alight
on it, and even enter it. The Oven-bird appears to drive them off with
screams of indignation, but the moment he retires they are about it
again, and, even when it contains eggs or young birds, begin impudently
carrying in feathers, straws, and other materials for a nest, as if they
were already in undisputed possession. At this stage the Tree-Martins
(_Progne tapera_) perhaps appear to complicate matters; and even if
these last comers do not succeed in ousting the Oven-birds, they are
sure to seize the oven when it becomes vacant, and the Sparrows, in
spite of their earlier claim, are left out in the cold. But they do not
take their defeat quietly, or, rather, they do not know when they are
beaten, but still remain to harrass their fellow-pirates, just as they
did the Oven-birds before, bringing straws and feathers in their
beaks, and when forced to drop these materials and chased from the
neighbourhood with great noise and fury by the Tree-Martins, it is only
to return undaunted in a few minutes, bringing more straws and feathers.
This Sparrow makes a rather large nest, neatly lined with horsehair,
and lays five eggs, long, pointed, the entire surface thickly marked
with deep chocolate-brown.
In rural districts this species is comparatively rare, not more than one
or two couples being seen about each habitation; and I scarcely think it
would be too much to say that there are four or five thousand Chingolos
for every individual Yellow Sparrow. Yet it is a hardy little bird, well
able to hold its own, subsists on the same kind of food and lays as many
eggs as the _Zonotrichia_; and it possesses, moreover, a great advantage
over the dominant species in placing its nest out of the reach of the
parasitical _Molothrus_, the destroyer of about fifty per cent. of the
Chingolo's eggs. I can only attribute the great disparity in the numbers
of the two species to the fact that the Yellow House-Sparrow will breed
only (out of towns) in nests not easily taken, and to the stubborn
pertinacity which leads it to waste the season in these vain efforts,
while the other species is rearing its brood. This is a blunder of
instinct comparable to that of the Minera (_Geositta cunicularia_),
mentioned by Darwin in the 'Voyage of a Naturalist,' where the bird made
its hole in a mud wall a few inches wide, and on coming out on the other
side simply went back and made another hole, and then another, unable to
understand that the wall had not the requisite width.
In such a case as the Yellow House-Sparrow presents, in which the colour
of the sexes differs, the female being without any of the brighter
hues found in the male, and which makes an elaborate nest and lays
deeply-coloured eggs, it is impossible not to believe that the bird
originally built in exposed situations, and subsequently--perhaps in
very recent times--acquired the habit of breeding in dark holes. The
frequent destruction of the exposed nest, and an abundance of vacant
domed nests, into which some individuals occasionally penetrated to
breed, would lead to the acquisition of such a nesting-habit; for the
birds inheriting it would have an advantage and be preserved, while
those persisting in the old habit of building exposed nests would
perish. Domed nests made by Dendrocolaptine birds are very abundant
even now, and it is probable that, before the country became settled by
Europeans, they were very much more numerous. Darwin, speaking of the
Oven-bird's habit of always placing its oven in the most conspicuous and
(to man) accessible places, predicts, and truly I believe, that this
habit will eventually cause the extinction of the species; for when the
country becomes more thickly settled, the bird-nesting boys will destroy
all the ovens. Probably when the Oven-birds were more abundant the
Sparrows could always find vacant ovens to breed in, until a habit of
breeding almost exclusively in these safe and convenient bird-built
houses was acquired; and the present seemingly stupid persistence of
the birds in struggling to get possession of those already occupied by
stronger species, only shows that the habit or instinct has not been
modified to suit a change in the conditions--_i. e._ a diminishing
number of ovens to breed in, with, perhaps, the increase of other
stronger species possessing the same habit. But while the instinct thus
survives too strongly in the country birds, many individuals have taken
to a town life, and acquired the new habit of breeding in holes in brick
walls. Probably this race of town birds will eventually colonize the
rural districts, and usurp the place of the country birds, which will
then be placed at a disadvantage.