(CHIMANGO CARRION-HAWK.)
+Milvago chimango+, _Scl. et Salv. Nomencl._ p. 122; _Durnford,
Ibis_, 1877, p. 40 (Chupat), et p. 188 (Buenos Ayres), et 1878,
p. 398 (Centr. Patagonia); _Gibson, Ibis_, 1879, p. 420 (Buenos
Ayres); _Barrows, Auk_, 1884, p. 111 (Entrerios); _Withington,
Ibis_, 1888, p. 470 (Lomas de Zamora). +Ibycter chimango+,
_Sharpe, Cat. B._ i. p. 41. +Milvago pezoporus+, _Burm. La-Plata
Reise_, ii. p. 434 (La Plata).
_Description._--Above reddish brown, with ashy edgings to the
feathers; rump greyish white; greater wing-coverts white, with
slight brown cross bars; primaries dark brown, externally at their
bases freckled with grey; inner webs at their bases white; tail
greyish white, with numerous freckles and narrow bands of brownish
grey: beneath grey, deeply tinged with rufous on the throat and
breast; crissum nearly white; under wing-coverts deep rufous; bill
pale yellowish; feet olive: whole length 15·0 inches, wing 11·0,
tail 6·5. _Female_ similar.
_Hab._ Southern half of South America.
Azara says of the Carancho (_Polyborus tharus_):--"All methods of
subsistence are known to this bird: it pries into, understands, and
takes advantage of everything." These words apply better to the
Chimango, which has probably the largest bill of fare of any bird, and
has grafted on to its own peculiar manner of life the habits of twenty
diverse species. By turns it is a falcon, a vulture, an insect-eater,
and a vegetable-eater. On the same day you will see one bird in violent
hawk-like pursuit of its living prey, with all the instincts of rapine
hot within it, and another less ambitious individual engaged in
laboriously tearing at an old cast-off shoe, uttering mournful notes the
while, but probably more concerned at the tenacity of the material than
at its indigestibility.
A species so cosmopolitan in its tastes might have had a whole volume to
itself in England; being only a poor foreigner, it has had no more than
a few unfriendly paragraphs bestowed upon it. For it happens to be a
member of that South-American subfamily of which even grave naturalists
have spoken slightingly, calling them vile, cowardly, contemptible
birds; and the Chimango is nearly least of them all--a sort of poor
relation and hanger on of a family already looked upon as bankrupt
and disreputable. Despite this evil reputation, few species are more
deserving of careful study; for throughout an extensive portion of South
America it is the commonest bird we know; and when we consider how
closely connected are the lives of all living creatures by means of
their interlacing relations, so that the predominance of any one kind,
however innocuous, necessarily causes the modification, or extinction
even, of surrounding species, we are better able to appreciate the
importance of this despised fowl in the natural polity. Add to this its
protean habits, and then, however poor a creature our bird may seem, and
deserving of strange-sounding epithets from an ethical point of view, I
do not know where the naturalist will find a more interesting one.
The Chimango has not an engaging appearance. In size and figure it much
resembles the Hen-harrier, and the plumage is uniformly of a light sandy
brown colour; the shanks are slender, claws weak, and beak so slightly
hooked that it seems like the merest apology of the Falcon's tearing
weapon. It has an easy loitering flight, and when on the wing does not
appear to have an object in view, like the Hawk, but wanders and prowls
about here and there, and when it spies another bird it flies after him
to see if he has food in his eye. When one finds something to eat the
others try to deprive him of it, pursuing him with great determination
all over the place; if the foremost pursuer flags, a fresh bird takes
its place, until the object of so much contention--perhaps after all
only a bit of skin or bone--is dropped to the ground, to be instantly
snatched up by some bird in the tail of the chase; and he in turn
becomes the pursued of all the others. This continues till one grows
tired and leaves off watching them without seeing the result. They are
loquacious and sociable, frequently congregating in loose companies of
thirty or forty individuals, when they spend several hours every day
in spirited exercises, soaring about like Martins, performing endless
evolutions, and joining in aerial mock battles. When tired of these
pastimes they all settle down again, to remain for an hour or so perched
on the topmost boughs of trees or other elevations; and at intervals
one bird utters a very long leisurely chant, with a falling inflection,
followed by a series of short notes, all the other birds joining in
chorus and uttering short notes in time with those of their soloist or
precentor. The nest is built on trees or rushes in swamps, or on the
ground amongst grass and thistles. The eggs are three or four in number,
nearly spherical, blotched with deep red on a white or creamy ground;
sometimes the whole egg is marbled with red; but there are endless
varieties. It is easy to find the nest, and becomes easier when there
are young birds, for the parent when out foraging invariably returns to
her young uttering long mournful notes, so that one has only to listen
and mark the spot where it alights. After visiting a nest I have always
found the young birds soon disappear, and as the old birds vanish also
I believe that the Chimango removes its young when the nest has been
discovered--a rare habit with birds.
Chimangos abound most in settled districts, but a prospect of food will
quickly bring numbers together even in the most solitary places. On the
desert pampas, where hunters, Indian and European, have a great fancy
for burning the dead grass, the moment the smoke of a distant fire is
seen there the Chimangos fly to follow the conflagration. They are,
at such times, strangely animated, dashing through clouds of smoke,
feasting amongst the hot ashes on roasted cavies and other small
mammals, and boldly pursuing the scorched fugitives from the flames.
At all times and in all places the Chimango is ever ready to pounce on
the weak, the sickly, and the wounded. In other regions of the globe
these doomed ones fall into the clutches of the true bird of prey; but
the salutary office of executioner is so effectually performed by the
Chimango and his congeners where these false Hawks abound, that the true
Hawks have a much keener struggle to exist here. This circumstance has
possibly served to make them swifter of wing, keener of sight, and
bolder in attack than elsewhere. I have seen a Buzzard, which is not
considered the bravest of the Hawks, turn quick as lightning on a
Cayenne Lapwing, which was pursuing it, and grappling it bear it down to
the ground and despatch it in a moment, though a hundred other Lapwings
were uttering piercing screams above it. Yet this Plover is a large,
powerful, fierce-tempered bird, and armed with sharp spurs on its wings.
This is but one of numberless instances I have witnessed of the extreme
strength and daring of our Hawks.
When shooting birds to preserve I used to keep an anxious eye on the
movements of the Chimangos flying about, for I have had some fine
specimens carried off or mutilated by these omnipresent robbers. One
winter day I came across a fine _Myiotheretes rufiventris_, a pretty
and graceful Tyrant-bird, rather larger than the Common Thrush, with
a chocolate and silver-grey plumage. It was rare in that place, and,
anxious to secure it, I fired a very long shot, for it was extremely
shy. It rose up high in the air and flew off apparently unconcerned.
What, then, was my surprise to see a Chimango start off in pursuit of
it! Springing on to my horse, I followed, and before going half a mile
noticed the Tyrant-bird beginning to show signs of distress. After
avoiding several blows aimed by the Chimango, it flew down and plunged
into a cardoon bush. There I captured it, and when skinning it to
preserve found that one small shot had lodged in the fleshy portion
of the breast. It was a very slight wound, yet the Chimango with its
trained sight had noticed something wrong with the bird from the moment
it flew off, apparently in its usual free buoyant manner.
On another occasion I was defrauded of a more valuable specimen than the
Tyrant-bird. It was on the east coast of Patagonia, when one morning,
while seated on an elevation, watching the waves dashing themselves on
the shore, I perceived a shining white object tossing about at some
distance from land. Successive waves brought it nearer, till at last
it was caught up and flung far out on to the shingle, fifty yards from
where I sat; and instantly, before the cloud of spray had vanished,
a Chimango dashed down upon it. I jumped up and ran down as fast as I
could, and found my white object to be a Penguin, apparently just killed
by some accident out at sea, and in splendid plumage; but, alas! in that
moment the vile Chimango had stripped off and devoured the skin from its
head, so that as a specimen it was hopelessly ruined.
As a rule, strong healthy birds despise the Chimango; they feed in his
company; his sudden appearance causes no alarm, and they do not take
the trouble to persecute him; but when they have eggs or young he is
not to be trusted. He is not easily turned from a nest he has once
discovered. I have seen him carry off a young Tyrant-bird (_Milvulus
tyrannus_), in the face of such an attack from the parent birds that
one would have imagined not even an Eagle could have weathered such a
tempest. Curiously enough, like one of the boldest of our small Hawks
(_Tinnunculus cinnamominus_), they sometimes attack birds so much too
strong and big for them that they must know the assault will produce
more annoyance than harm. I was once watching a flock of Coots feeding
on a grassy bank, when a passing Chimango paused in its flight, and,
after hovering over them a few moments, dashed down upon them with such
impetuosity that several birds were thrown to the ground by the quick
successive blows of its wings. There they lay on their backs, kicking,
apparently too much terrified to get up, while the Chimango deliberately
eyed them for some moments, then quietly flew away, leaving them to dash
into the water and cool their fright. Attacks like these are possibly
made in a sportive spirit, for the Milvago is a playful bird, and, as
with many other species, bird and mammal, its play always takes the form
of attack.
Its inefficient weapons compel it to be more timid than the Hawk, but
there are many exceptions, and in every locality individual birds are
found distinguished by their temerity. Almost any shepherd can say
that his flock is subject to the persecutions of at least one pair of
lamb-killing birds of this species. They prowl about the flock, and
watch till a small lamb is found sleeping at some distance from its dam,
rush upon it, and, clinging to its head, eat away its nose and tongue.
The shepherd is then obliged to kill the lamb; but I have seen many
lambs that have been permitted to survive the mutilation, and which have
grown to strong, healthy sheep, though with greatly disfigured faces.
One more instance I will give of the boldness of a bird of which Azara,
greatly mistaken, says that it might possibly have courage enough to
attack a mouse, though he doubts it. Close to my house, when I was a
boy, a pair of these birds had their nest near a narrow path leading
through a thicket of giant thistles, and every time I traversed this
path the male bird, which, contrary to the rule with birds of prey,
is larger and bolder than the female, would rise high above me, then
dashing down, strike my horse a violent blow on the forehead with
its wings. This action it would repeat till I was out of the path.
I thought it very strange the bird never struck _my_ head; but I
presently discovered that it had an excellent reason for what it
did. The gauchos ride by preference on horses never properly tamed,
and one neighbour informed me that he was obliged every day to make
a circuit of half a mile round the thistles, as the horses he rode
became quite unmanageable in the path, they had been so terrified
with the attacks of this Chimango.
Where the intelligence of the bird appears to be really at fault is in
its habit of attacking a sore-backed horse, tempted thereto by the sight
of a raw spot, and apparently not understanding that the flesh it wishes
to devour is an inseparable part of the whole animal. Darwin has noticed
this curious blunder of the bird; and I have often seen a chafed
saddle-horse wildly scouring the plain closely pursued by a hungry
Chimango determined to dine on a portion of him.
In the hot season, when marshes and lagoons are drying up, the Chimango
is seen associating with Ibises and other waders, standing knee-deep in
the water and watching for tadpoles, frogs, and other aquatic prey. He
also wades after a very different kind of food. At the bottom of pools,
collected on clayey soil after a summer shower, an edible fungus grows
of a dull greenish colour and resembling gelatine. He has found out that
this fungus is good for food, though I never saw any other creature
eating it. In cultivated districts he follows the plough in company with
the black-headed gulls, Molothri, Guira cuckoos, and tyrant-birds, and
clumsily gleans amongst the fresh-turned mould for worms and larvæ. He
also attends the pigs when they are rooting on the plain to share any
succulent treasure-trove turned up by their snouts; for he is not a bird
that allows dignity to stand between him and his dinner. In the autumn,
on damp, sultry days, the red ants, that make small conical mounds on
the pampas, are everywhere seen swarming. Rising high in the air they
form a little cloud or column, and hang suspended for hours over the
same spot. On such days the Milvagos fare sumptuously on little insects,
and under each cloud of winged ants several of them are to be seen in
company with a few Flycatchers, or other diminutive species, briskly
running about to pick up the falling manna, their enjoyment undisturbed
by any sense of incongruity.
Before everything, however, the Chimango is a vulture, and is to be
found at every solitary rancho sharing with dogs and poultry the offal
and waste meat thrown out on the dust-heap; or, after the flock has
gone to pasture, tearing at the eyes and tongue of a dead lamb in the
sheepfold. When the hide has been stripped from a dead horse or cow on
the plains, the Chimango is always first on the scene. While feeding
on a carcass it incessantly utters a soliloquy of the most lamentable
notes, as if protesting against the hard necessity of having to put up
with such carrion fare--long, querulous cries, resembling the piteous
whines of a shivering puppy chained up in a bleak backyard and all its
wants neglected, but infinitely more doleful in character. The gauchos
have a saying comparing a man who grumbles at good fortune to the
Chimango crying on a carcass; an extremely expressive saying to those
who have listened to the distressful wailings of the bird over its meat.
In winter a carcass attracts a great concourse of the Black-backed
Gulls; for with the cold weather these vultures of the sea abandon their
breeding-places on the Atlantic shores to wander in search of food over
the vast inland pampas. The dead beast is quickly surrounded by a host
of them, and the poor Chimango crowded out. One at least, however, is
usually to be seen perched on the carcass tearing at the flesh, and
at intervals with outstretched neck and ruffled up plumage uttering
a succession of its strange wailing cries, reminding one of a public
orator mounted on a rostrum and addressing harrowing appeals to a crowd
of attentive listeners. When the carcass has been finally abandoned
by foxes, armadillos, gulls, and caracaras, the Chimango still clings
sorrowfully to it, eking out a miserable existence by tearing at a
fringe of gristle and whetting his hungry beak on the bones.
Though an inordinate lover of carrion, a wise instinct has taught it
that this aliment is unsuited to the tender stomachs of its fledglings;
these it feeds almost exclusively on the young of small birds. In
November the Chimangos are seen incessantly beating over the cardoon
bushes, after the manner of Hen-harriers; for at this season in the
cardoons breeds the _Synallaxis hudsoni_. This bird, sometimes called
_Téru-réru del campo_ by the natives, is excessively shy and mouse-like
in its habits, seldom showing itself, and by means of strong legs and
a long, slender, wedge-like body is able too glide swiftly as a snake
through and under the grass. In summer one hears its long melancholy
trilling call-note from a cardoon bush, but if approached it drops to
the ground and vanishes. Under the densest part of the cardoon bush it
scoops out a little circular hollow in the soil, and constructs over it
a dome of woven grass and thorns, leaving only a very small aperture: it
lines the floor with dry horse-dung, and lays five buff-coloured eggs.
So admirably is the nest concealed that I have searched every day for
it through a whole breeding-season without being rewarded with a single
find. Yet they are easily found by the Chimango. In the course of a
single day I have examined five or six broods of young Chimangos, and
by pressing a finger in their distended crops, made them disgorge their
food, and found in every instance that they had been fed on nothing but
the young of the _Téru-réru_. I was simply amazed at this wholesale
destruction of the young of a species so secret in its nesting-habits;
for no eye, even of a Hawk, can pierce through the leafage of a cardoon
bush, ending near the surface in an accumulated mass of the dead and
decaying portions of the plant. The explanation of the Chimango's
success is to be found in the loquacious habit of the fledglings it
preys on, a habit common in the young of Dendrocolaptine species. The
intervals between the visits of the parent birds with food they spend in
conversing together in their high-pitched tones. If a person approaches
the solid fabric of the Ovenbird (_Furnarius rufus_), when there
are young in it, he will hear shrill laughter-like notes and little
choruses, like those uttered by the old birds, only feebler; but in the
case of that species no harm can result from the loquacity of the
young, since the castle they inhabit is impregnable. Hovering over
the cardoons, the Chimango listens for the stridulous laughter of the
fledglings, and when he hears it the thorny covering is quickly pierced
and the dome broken into.
Facts like this bring before us with startling vividness the struggle
for existence, showing what great issues in the life of a species may
depend on matters so trivial, seemingly, that to the uninformed mind
they appear like the merest dust in the balance, which is not regarded.
And how tremendous and pitiless is that searching law of the survival
of the fittest in its operations when we see a species like this
_Synallaxis_, in the fashioning and perfecting of which nature seems
to have exhausted all her art, so exquisitely is it adapted in
its structure, coloration, and habits to the one great object of
concealment, yet apparently doomed to destruction through this one petty
oversight--the irrepressible garrulity of the fledglings in their nest!
It is, however, no oversight at all; since the law of natural selection
is not prophetic in its action, and only preserves such variations as
are beneficial in existing circumstances, without anticipating changes
in the conditions. The settlement of the country has, no doubt, caused
a great increase of Chimangos, and in some indirect way probably has
served to quicken their intelligence; thus a change in the conditions
which have moulded this _Synallaxis_ brings a danger to it from an
unexpected quarter. The situation of the nest exposes it, one would
imagine, to attacks from snakes and small mammals, from bird-killing
spiders, beetles, and crickets, yet these subtle ground foes have missed
it, while the baby-laughter of the little ones in their cradle has
called down an unlooked-for destroyer from above. It might be answered
that this must be a very numerous species, otherwise the Chimango could
not have acquired the habit of finding the nests; that when they become
rarer the pursuit will be given over, after which the balance will
readjust itself. But in numbers there is safety, especially for a feeble
hunted species, unable from its peculiar structure to vary its manner of
life. To such, the remark made by Darwin, that "rarity is the precursor
to extinction," applies with peculiar force.