BIRD-NESTING IN NORTHWESTERN ARGENTINA
La Quiaca is similar in size and appearance to Villazón. There are a
number of stores or trading-posts where miners from the surrounding
mountains secure their outfits and provisions. It is also the terminus
of the railroad from the south. One may go by rail directly to Buenos
Aires. The settlement stands on a level, wind-swept plateau, and the
weather was very cold. The neighboring peaks of the Andes are rich in
mines, and multitudes of llamas and mules come down the steep trails
each day, laden with copper, bismuth, silver ore, and gold ore. They
discharge their burdens at the railroad-station, where it is loaded on
cars to be hauled to the smelters in Buenos Aires.
Our object in coming to the Argentine was to continue the biological
survey we had carried on in Bolivia; and also to secure specimens of
a rare little bird (_Scytalopus_) which was thought to exist in the
province of Salta. The acquisition of this bird was most important for
the light it would throw on certain problems of distribution.
The little wren-like birds of this genus (_Scytalopus_), known commonly
as “tapacolas,” are perhaps among the most difficult to collect of
any species in South America, and for this reason they are invariably
only poorly represented in museum collections. Native collectors,
hunting mainly with blow-guns, have gathered many thousands of birds,
the greater number of which have eventually found their way to
millinery establishments and scientific institutions in many parts of
the world; but usually only those of brilliant plumage, and others
which could be taken with little difficulty, have been collected. The
small, slate-colored or blackish tapacolas, found only in the densest
of subtropical forests or among the tangled vegetation bordering
bleak, frigid _paramos_, have usually been overlooked. This is not
surprising when we find how seldom even the trained field-naturalist
of to-day finds it possible to lure the tiny, feathered creature from
its secure retreat among the mosses, roots, and ferns to which its
mouse-like habits confine it, and how rarely he succeeds in recovering
the inconspicuously colored bird after it has been shot. Even after a
long, patient search has revealed the specimen lodged somewhere in the
deep stratum of matted plants, it is by no means sure of reaching the
museum; I know of instances where birds, slipping from the hunter’s
hands and dropping at his feet, have been forever lost in the riot of
vegetation which everywhere carpets the ground.
Our quest for this little creature was destined to extend over a period
of months, and to take us into many an out-of-the-way place. We were
eager to begin the search, so took the first available train which left
La Quiaca two days after our arrival and started southward.
Leaving the desolate settlement, the railroad winds upward through
a narrow, rocky gorge to the station Tres Cruces, the altitude of
which is twelve thousand four hundred feet. There it descends at a
steep grade--so steep in fact that a rack and pinion are used part
of the way. The rocky knobs flanking the gorge are old and weathered
and very picturesque. A small stream winds back and forth across a
boulder-strewn course; the water is clear and cold. About mid-afternoon
we encountered an abrupt change in the type of country. The bare crags
and narrow, rocky floor of the gorge gave way to a wide expanse of
brush-covered land and green pasture. This change was first noticeable
at a small station called Leon (elevation five thousand feet); the
vegetation grew thicker and the landscape more inviting as we continued
the journey. At dusk we reached Jujuy, a city of some pretensions;
the buildings are attractive, the streets are broad, and the people
appeared clean and intelligent. Following Jujuy were numerous small
towns and stations; also many truck-farms owned by Italians who were
settling in Argentina in great numbers. There were also vast green
meadows in which fine-looking cattle, horses, and sheep were grazing.
Our first stop was at Salta. The journey from La Quiaca had required
fifteen hours.
Salta has about thirty thousand inhabitants, and is a modern city.
It possesses wide, paved streets, buildings of imposing dimensions,
electric trolleys, and lights, a zoological park, good hotels, and
a college. The contrast between being in a city where comforts and
luxuries abounded, and living on the bleak, Andean uplands amidst
stolid Quechuas guarding their herds of llamas, was great, and we
enjoyed the change to the fullest extent. After frozen potatoes and
canned provisions, the inviting coffee-houses were irresistible;
and the “movies” made us forget the miles of inhospitable desert.
Fortunately there were enough of each of these attractions so that we
could spend a whole day visiting them, alternating from one to the
other, without repeating.
Our first headquarters in the Argentine were made at Rosario de Lerma,
one hour by train from Salta. This is a most delightful spot and
afforded rare opportunities for work and observation. The town contains
about one hundred houses and is surrounded by fields, pastures, and
patches of low, open woods. There is an abundance of water, and
excellent meat, fruits, and vegetables may be had in abundance.
The people are industrious and of good appearance, and treated us
courteously.
We soon discovered that in Argentina we were not at liberty to carry
on our work in any place or manner that suited our purpose; in other
words, there were game-laws, closed and open seasons, and it was
necessary to secure permits from the owners of all lands on which we
proposed to hunt. Of all these restrictions we were ignorant, and
spent a blissful three days doing as we pleased; then a sergeant of
police called and notified us that we were under arrest, and to call at
headquarters as soon as convenient. I lost no time in going to see the
chief, explained the nature of our work to him, and then acting on his
suggestion took the next train to Salta to get a permit which entitled
us to hunt anywhere within that province. All this was accomplished
within a few hours. The various officials with whom I came in contact
were most courteous and obliging.
Our study of bird-nesting at Rosario de Lerma was confined largely
to observing the parasitic habits of the black cowbird (_Molothrus
b. bonariensis_), referred to by the Spanish-speaking people as the
“tordo.” The bird usually called tordo, however, is a species of
oriole, highly esteemed as a cage bird on account of its not unmusical
singing ability. This bird is of slender, graceful build, about the
size of a red-winged blackbird, and of a uniform glossy, purplish-black
color except on the wings and tail, which have a pronounced greenish
sheen. The female is of a dark, ashy-brown color.
We saw flocks of them daily in the fields, on the backs of cattle
grazing in the pastures, in the courtyards of houses, in corrals, and
more particularly in the scattered trees, which were almost certain
to contain at least one nest of the oven-bird (_Furnarius_) or of
some species of brush-bird (_Phacellodomus_). Usually the flocks were
composed of from ten to twelve individuals, the bright, glossy males
outnumbering the dull, grayish females in the proportion of four to
one. Azara gives the proportion of males to females as ten to one, but
this disparity is too great for any part of the Argentine known to me.
The birds are noisy, keeping up a loud chatter, especially where a
flock is on the wing, or when preparing for the night’s sleep. The male
bursts into a short, pretty song with frequency, dropping his wings and
moving in a nervous manner while singing. Apparently the female does
not sing.
It has been said that the females of this species lay eggs during a
period of three or four months; to know how many are laid by a single
bird would be interesting, as the number must be very great in order
to make allowance for the incalculable numbers that are wasted, and
still provide enough to keep the ranks of the multitudes at their
normal level.
We did not find a single egg of _M. b. bonariensis_ on the ground,
although Hudson states that in the vicinity of Buenos Aires these birds
“frequently waste their eggs by dropping them on the ground.”
Dropping the eggs on the ground might entail a deliberate waste, as
we know of no reason why the bird should suppose that they would be
hatched and the young reared, if scattered broadcast over the country.
On the other hand, this might merely indicate that the birds had found
no suitable place in which to deposit their eggs. The form of waste
caused by the birds laying in old, disused nests, or by laying such a
large number of eggs in a single nest that it is impossible for the
rightful owner to incubate them and rear the young, can hardly be said
to be deliberate, as it is doubtless caused by a lack of intelligence;
if the bird designedly scatters its eggs broadcast on the ground, it is
wantonly wasteful; if it merely lays in disused nests, or overcrowds
nests actually occupied, the bird may simply be stupid.
It would be impossible to say what per cent of eggs laid by this
species of cowbird is wasted. Hudson estimates that each female lays
from sixty to one hundred eggs in a single season, and it does not
seem to me that this statement is an exaggeration. One female which
I dissected had laid three eggs within the few preceding days, and a
fourth was almost ready to be deposited.
The bird which suffers most from the parasitic habits of the cowbird
in the vicinity of Rosario de Lerma, is the oven-bird (_Furnarius
rufus_); however, of the great number of eggs laid in the nests of the
above-named species, our observations tend to show that the greater
part are lost. Among the scores of oven-bird nests which we examined,
only two were still occupied by the owners, the desertion being
apparently due to the invasion of the cowbirds. So persecuted were the
oven-birds that it is difficult to understand how any of them survived
in this immediate locality. The nests were common enough, it being
not unusual to find several of them in a single tree, but the birds
themselves were not abundant. It is possible that some of the pairs
may have built several nests each in their vain attempts to escape the
attentions of the cowbirds.
In no instance had the walls or top of the oven-birds’ nests been
broken or perforated in any manner, in order that light could
penetrate to the interior; they were not tampered with in any way, and
the cowbirds seemed content to use them just as the oven-birds had
constructed them.
I believe that the greater number of _M. b. bonariensis_ that reach
maturity are reared by the smaller birds, such as finches, warblers,
and vireos, in whose nests only a few eggs are laid, which increases
the favorable chances of their incubation. Also, the larger and heavier
eggs of the cowbird frequently crush at least a part of the smaller
eggs which naturally have a more fragile shell, thus forestalling to a
marked degree the competition that might arise between the young birds
in the nest.
We collected about two hundred eggs of this species, nearly all of
them at Rosario de Lerma, and a great variation in marking exists;
there is also some difference in color. As a general rule the eggs are
greenish or bluish, rather heavily spotted with reddish-brown; in a
very few specimens the background is of a pale flesh-color, and in a
small number of others it approaches white, having, however, a dull
grayish tinge; of the entire lot, four only are so lightly marked as to
appear unspotted. Not a single egg is pure white or has a pure white
background (my standard of comparison is an egg of the oven-bird) “like
the eggs of birds that breed in dark holes”; the majority of these eggs
were taken from the darkened interiors of oven-birds’ nests.
A type of egg not uncommon is heavily and evenly marked all over with
fine dots and larger spots of reddish-brown. Judging from the material
at hand I should say that there is a characteristic type of marking
running through the eggs of the species if we except the two extremes,
_viz._, those almost unspotted, and those so entirely covered with
heavy blotches that they appear to be of a uniform chocolate color.
However, the eggs of each individual seem to vary in some respect from
those of any other, as it is impossible to find two exactly alike in
comparing series from different places. Frequently, two or more eggs
found in the same nest resemble each other so closely in size, shape,
and coloration, that I think it reasonably safe to say that they were
laid by the same bird.
The nests of the smaller birds contained from one to four eggs of these
parasites, in addition to those of the rightful owners. On January 12,
I opened an oven-bird nest and was surprised to find fifteen cowbirds’
eggs in the dark interior. This I considered a record, but Boyle
brought one in on the same day containing twenty-six of the speckled
eggs. In the days that followed, we discovered numerous “sets” of from
ten to twenty. The nest that contained the final record number was
found January 16, it contained thirty-eight eggs--one of the oven-birds
and thirty-seven of the cowbirds.
Later, we again met these old acquaintances wintering in the
rice-fields and rush-grown marshes of Tucuman.
The white ani (_Guira guira_) or Guiraca, first seen near Asuncion,
and later in Bolivia, was plentiful at Rosario de Lerma. The bird was
usually found in small flocks and fed on the ground.
We found several of their nests near Rosario de Lerma. They were large,
loosely built of sticks and placed in the crotch of a cactus or other
thorny plant, at no great height from the ground. However, the nest is
not conspicuous in spite of its size.
Pablo Girard, an Argentine naturalist, informed me that these birds
frequently nest in communities and that a number of females lay their
eggs in the same nest, although this is not always the case. The
natives verified this statement. This seems probable as I at no time
saw the groups split up into pairs; on the contrary, there were always
numbers of birds in the vicinity of each domicile. Our record set
contained twelve eggs.
After ten days at Rosario de Lerma, we returned to Salta and then took
the train to Perico, a ride of three and a half hours northward. At
this station a branch railroad runs northeastward into Argentina’s
vast Chaco region. The track was being extended as rapidly as labor
and material can be obtained for the work, and we desired to go to the
end of the line where is located a station called Embarcacion. Before
starting on this journey, however, we spent some time at points noted
on the downward journey from La Quiaca. Perico is a busy little town,
owing its activity to the traffic occasioned by the railroad junction.
The buildings are low and dilapidated, and most of them consist of a
shop, or _venta_, in front, with living-rooms in the rear.
The shops are always worthy of exploration. In some, huge piles
of watermelons were displayed for sale; others offered fruits and
vegetables, and still others groceries and dry-goods. Drinking-places
were abundant.
We were particularly interested to find numbers of rhea eggs on sale
in the outdoor market. They brought forty _centavos_ each and were
delicious; the contents of each was equal to about a dozen hen’s eggs.
I was told that they were gathered from the nests of wild birds in the
Chaco. Each nest contains from ten to twenty or even thirty eggs, which
are more than one man can carry. When fresh, the shell is of a deep
cream-color; after incubation has started or if the egg is addled, the
color is pale, ashy gray. The birds are killed and eaten--the flesh
resembling that of a goat’s in flavor.
One day a number of Indians arrived from San Pedro. They brought huge
baskets and crates of young amazon parrots. These birds are taken when
very young from nests placed in the cavities of trees, and are reared
by hand until they are able to eat unaided. Usually two are found in
a nest--occasionally three. They also brought a tame coypu rat and
several three-banded armadillos.
Perico is surrounded by miles of cattle lands, light woods, and limited
areas covered with vegetation of a semiarid type. In the latter places
small deer or brockets are not uncommon; they hide in the low, thorny
growth of Spanish bayonet until one is within a few yards of them, then
dash away at great speed; the inhabitants hunt them with dogs trained
for the purpose, and rarely fail to bag their quarry, though usually
after a long chase.
We found the coral-billed tinamou not uncommon in the wooded districts.
They are essentially birds of the tree-covered regions and are
difficult to secure on account of their terrestrial habits, and also
owing to the fact that they adhere closely to the densest cover. I have
on a number of occasions seen captive specimens, but they seem to not
take kindly to the restricted life of a cage or aviary, and spent most
of the time dashing wildly about, injuring themselves so seriously that
they did not long survive.
A number of the birds of this locality are not included in the avifauna
of Rosario de Lerma, but belong to the Chaco type, and I recognized
some species which were common near Asuncion, Paraguay; among them a
large blue jay and a brown-shouldered oriole.
Our next station was at Volcan. About the only attractive thing about
this place was a great lake almost entirely surrounded by high hills,
and teeming with water-fowl. The Quechua boy we had brought from
Bolivia was the first to find the lake. He rushed back to us excitedly
with the information that there was a large body of water near by with
a huge, white duck on it; he had shot at the queer bird, that had a
black neck, a number of times but failed to hit it. Fortunate for
all of us that his marksmanship was poor! The “duck” was of course
a black-necked swan belonging to the owner of the terrain, and its
untimely demise would have cost us dearly. There were, however,
hundreds of ducks; teals, ruddies, shovellers, and pintails; also, many
coots, grebes, and rails.
The body of water had an area of over a square mile, and in its edges
a tall fringe of cattails grew. Marsh-wrens and military flycatchers
haunted these swaying green thickets, and grebes stole silently in and
out of their ragged borders. There were many disused nests of coots and
ducks; but while making our way through the high, tangled growth we
came suddenly upon the nest of a giant grebe (_Fulica gigantica_); it
consisted of a huge mass of reed stems, slightly concave on top, and
extending about a foot above the water; in it were four pointed, brown
eggs, heavily dotted with deep brown and black. This was apparently a
second clutch, the first, perhaps, having been destroyed. There were
scores of other nests, but all were empty and falling into decay.
We spent a busy day tramping about the borders of the hidden lake,
watching the flocks of coming and departing ducks and bagging such as
we needed--whenever a duck or cormorant plumped into the water Boyle
swam out and got it; this was risky work that I did not encourage,
as the water was ice cold and many fathoms deep, and the ensnaring
under-water growths of reeds and cattail stems formed dense, slimy
masses capable of holding a man who might become entangled in them
until he became exhausted and drowned.
While at Volcan we stayed at the house of an Italian trader. He asked
if we had any recent reports of the war, and then expressed the hope
that it would last years longer, as he owned part interest in a
copper-mine, and was receiving war prices for the much-needed metal.
We decided not to accept his hospitality any longer and took the train
to Tilcara. I have often met foreigners in South America (including
some from the United States) who were representative of anything but
the better class of citizens of their respective countries; it is
unfortunate that many Latin Americans base their estimate of a people
upon the appearance and doings of these few misguided and objectionable
characters.
[Illustration: Ploughing at Rosario de Lerma.]
[Illustration: Tilcara, showing the stream and valley and the
snow-capped Andes in the distance.]
At Tilcara we lived with another Italian family, but of an entirely
different type. The village, the elevation of which is eight thousand
feet, stands about half a mile from the railway-station. We were
engaging _peons_ to carry our luggage there when the man stepped up
and offered us the use of part of his humble home, which stood within
a hundred feet of the spot. We accepted the invitation, and during our
entire stay were treated with great courtesy.
There is a narrow valley between high, rugged, barren peaks, some of
which are snow-capped. Parts of the depression are dry and semiarid;
others, marshy and covered with high, rank grass. Small Indian huts
built of stones or adobe are strewn about, and there are numerous
fields from which the rocks have been gathered through years of effort
so that the land may be cultivated.
There were many birds. They represented a fauna intermediate between
that of the high, cold plateau and that found lower down at Rosario de
Lerma. Large red-breasted meadow-larks (_Troupialis_) were common and
always found in pairs. Of hummers there were numerous kinds, attracted
by clumps of flowering shrubs that grew alongside the fences; the giant
humming-bird and the gorgeous coppery-tailed comet were particularly
plentiful. The former are very stupid. They came fluttering along like
awkward swallows and often settled comfortably on a branch near to us,
from which they would inspect us at their leisure, while they chirped
and darted out the tongue like a snake. One of the comets that we
collected had eaten quantities of gnats and small ants.
The walls of a deserted Quechua hut had been appropriated by a flock
of bay-winged cowbirds (_Molothrus badius_) for their nesting-sites.
Dozens of small, round holes penetrated the thick, earthen walls, and
some of them extended entirely through; the latter were not occupied.
Apparently whatever birds had drilled the cavities, frequently
surprised themselves by emerging suddenly into the daylight they were
trying to get away from, at the far end of the burrow. However, not
to be discouraged, repeated other attempts were made, some of which
were successful as the walls varied in thickness. A small, flat nest
of sticks lined with a few feathers comprised the bay-wing’s domicile.
Some of them contained young birds, and one had five eggs in it. The
adult birds always remained in a flock in the vicinity and kept up a
shrill screaming while we were near.
Large, blackish rails inhabited the reedy marshes; they came in flocks
to feed in the velvety green islands interspersed among the weed and
water covered areas. Watching from a concealed position, we could see
them strut unconcernedly about, flicking their tails over their backs
and jerking their necks and picking up the tiny mollusks and insects
that were so abundant. When alarmed they craned their necks, looked
about inquisitively, then gave a few hoarse cackles and ran into the
weeds; within a few moments they returned, one at a time, and at first
slowly and cautiously; but soon, forgetting that danger might lurk
near by, they rushed for the spots where food was most abundant. Rails
are peculiar and interesting birds. The body is narrow and compressed
like a flea’s; this enables them to slip through the dense reeds and
water-plants in which they live. The comparatively long bills make
it possible for them to pick up food in shallow water. Their long,
slender toes, giving the feet a wide spread, make walking on floating
vegetation and soft mud easy; nevertheless, at least some species are
good swimmers.
Flocks of night-herons spent the days in a small clump of willows
fringing the marsh. At dusk they grew very active and we could hear
them croaking from afar. They are splendid eating.
As at Pulqué and the Pilcomayo, birds were hard pressed for
nesting-sites. Giant club-cacti apparently were at a premium. The
old, disused nests of brush-birds (_Synallaxis_), or _leñateros_, were
inhabited by mocking-birds which built a nest of their own within
the huge structure of twigs; and, when the mocking-birds were away,
cowbirds slipped in and deposited a few eggs. One mocking-bird had been
so unwise as to place its nest in a thorny bush covered with dense
foliage so that it could not be watched from a distance and defended
from cowbirds; before the owners were ready to use their new home, it
had received many visits from the black parasites (_M. b. bonariensis_)
who left their cards in the shape of fourteen speckled eggs. We
collected this “set” but have the idea that this only encouraged the
cowbirds to increased efforts.
The abundance of ducks in South America in places where one least
expects to find them, is a source of never-ending surprise. A small
stream flows through the valley at Tilcara. It is nowhere more
than twenty feet across, and two or three feet deep, but flocks of
green-winged teals visited it regularly at dawn and dusk. They swam in
the rapid water, and then lined up on the rocky bank for a quiet nap.
The inhabitants of Tilcara shot many, but others came to the same place
daily.
Of mammals there were but few. Cavies, as usual, lived among the
rock piles and in the stone fences, and a few other small rodents
inhabited the grain-fields. One day we secured a fine specimen of
the rare, elusive yellow cat called _gato pampero_, or pampas-cat.
It was stealing cautiously along the river-bank; but I am unable to
say whether it had come in quest of fish or merely for the purpose
of quenching its thirst. Our work in this region being completed, we
returned to Perico, and prepared for the journey to Embarcacion.