as there are among the banner-decked processions of the leaf-cutters.
Along the tree-trunk track came three big white-heads straddling an
inch-worm--in this case an inch-and-a-half-worm. They leaned forward and
downward, the heads of those behind overlapping the abdomens in front,
and they looked for all the world like the riders of an old-fashioned
three-seated bicycle, spurting along the trail. Another simile, even
more vivid, evoked the vision of some weirdly constructed, elongated
myriopod with eighteen legs. After a hard fight, in the course of which
I was stung twice, I unseated the trio and took the measuring worm away
from them. As I lifted it from where it had fallen, at least fifty ants
hurled themselves at the spot, jaws snapping, trembling with violent
rage. I walked ten feet away and dropped the worm in the midst of
another column, and within an equal number of seconds three new
white-heads had mounted it and were hustling it along--the replicas in
appearance and method of the first team.
Many species of stranger ants were killed and carried off as food, but
now and then I noted a most significant exception. In three different
parts of the glade I saw good-sized, pale, flesh-colored ants which
walked unharmed in the very ranks of the terrible host. Unharmed they
were, but not wholly above suspicion, and their progress was not an easy
one. For every unburdened ant which passed leaped at the pale one,
antennaed it fiercely for a moment and reluctantly released it. One
could read their indecision as they slowly loosened their hold, turning
again and again and waving their antennae as if to make sure that it was
not better to act on their suspicion and slay at once. Finally, they
always passed on. The pale ones had some strange inaudible password,
some sensory parole which protected them. And their total lack of fear
showed their knowledge of their immunity. Even with the added sense of
sight which they possessed, they chose voluntarily to accept this
dubious, reluctantly accorded friendship. But it was probable that, even
if they lived in the very community or nest of the army ants, theirs was
the hard-earned dependence of neutrals who were liable to be knocked
down at a moment's notice, and searched for any strange, inimical scent
which would spell instant death.
In one place the army column made a slight detour round a hillock of
sandgrains upon which a host of tiny brown ants was laboring. I thought
it remarkable that such immunity should be accorded these dwarfs, and I
sought the reason. It was forthcoming at once when I gingerly lifted a
big soldier with the forceps and dropped him on the ant-hill. What
occurred was a replica of the usual army ant scene, but enacted as if
viewed through the large end of an opera-glass. Scores of the minute
brown chaps rushed forth and for a moment fairly overbore the
white-headed giant. Indeed, before he could recover he was dragged
partly down a sandy hole. His jaws brandished and champed, but his
assailants were so small that they slipped through them unharmed. Many
actually seized the jaws themselves and were hurled through the air as
they snapped together. Regaining his feet, the great army ant staggered
off and, fortunately for him, rolled down a slope into another column of
his own kind. Here he freed himself little by little, scraping off the
minute fighting browns with the help of two very small workers, whose
jaws, being much less in size, were better able to grip the diminutive
furies. Their assistance was half-hearted, and the odor of the dead and
dying pygmies was distinctly disliked by them. They were apparently well
aware of the capabilities of these small cousins, and held them in high
respect. This outburst of successful defense on the part of the small
ants was unexpected. I glanced back at their hill and saw them
unconcernedly piling up grains as if nothing had occurred to disturb
them. I wondered if, with senses perfectly attuned, with an
enlarging-glass ability of observation, one might not find still lesser
communities which would in their turn consider the little brown ants as
giants, and on the space of a pin's head attack them and fly at their
throats.
A species of silvery-gray ant which was abundant in the glade was an
object of special enmity, and even after one of these was killed and
being carried along, passing army ants would rush up and give it a
vicious, unnecessary nip. One such ant made its escape from the hold of
a small worker; but before it had taken ten steps it was actually buried
under a rolling mass of army ants. The flying leap with which these
athletes make their tackle would delight the heart of any football
coach, although their succeeding activities belong rather to savage
warfare. Termites, or so-called white ants, are, curiously enough,
immune from attack. Yet these slow-moving, fat-bodied creatures would
seem first-rate food, and the fight which they could put up would not
stand an instant before a concerted rush of battling army ants. The
saving character is doubtless odor or taste. I dropped a tunnelful of
these insects in the path of the army ants and they were quite ignored,
although the black-and-white-headed fellows were terribly angry and
excited.
I coveted a small beetle of peculiar pattern which the ants were
hurrying along, and in taking it from them I accidentally cut an army
ant in two. His abdomen rolled down a small slope and caused
considerable panic among his fellows. They formed a ring round it and
waved their antennae in mid-air, the scent of the blood of their own kind
causing them to forget hurry and burdens and their normal activities.
The front part of the ant seemed but little inconvenienced and
endeavored to seize and carry the load it had dropped. Little by little
it began to realize that all was not right, and after one or two
attempts to turn and investigate, it ran rapidly down the trail. I made
a dab at it to put it out of what seems better called inconvenience than
misery, but succeeded only in bisecting the thorax, so that there
remained the head and front pair of legs. These lost nothing in
activity, and by means of the single pair of legs the head rowed itself
rapidly along, its antennae twiddling vigorously those of every ant it
met. This was uncanny, a little too much, and I ground the fraction of
ant to powder. No wonder the army ant is such a virile creature, endowed
with the most extreme emotions, when, with such a small section of its
anatomy remaining it can continue to show such astounding activity.
One could study for hours the interactions among the army ants
themselves. More than once I saw a good-sized ant transporting one of
its fellows, exactly as it would carry a bit of booty. I tried to
examine this ant, and to my surprise, both attacked me ferociously. The
one which was carried was neither dead, ill, nor disabled, but very much
alive. I cannot even suggest an explanation of this phenomenon, as it
did not seem an attempt to aid a comrade in distress.
As dusk began to settle down, I found a column of ants which must have
discovered and sacked the city of some stranger ants. They were laden
with ant-booty: eggs, larvae, and dead ants by the hundred. It was
comprehensible, but what I did not at first understand was a dense line
of ants moving solidly in one direction, all laden with large eggs and
immature ants, which they were carrying with great care. A large number
of the huge soldiers patrolled the outer flanks of the column, more than
I had seen with all the other traffic lines together. I realized at last
that I was looking at an actual moving of a portion of the army ant
household itself. It was guarded and transported with all the care of
which these insects were capable. The infant ants rested safely in the
great jaws, the same jaws which all day had been busy slashing and
biting and tearing, and carrying food for these same infants.
And now the tropical night began to close down and I made my way back to
the sandpit. The last of the columns was making its way out,
systematically from the bottom up, each ant following in turn. The
moment the last bit of prey passed up the column, by some wonderfully
delicate and subtile sense, every ant knew of it, and the corduroy rose,
the hand-rails unjointed themselves, the ropes unspliced, the embankments
dislodged of their own volition, and stepping-stones took to themselves
legs. After hours of total inactivity, these sentient paraphernalia of
the _via formica_ became, once more, beings surcharged with ceaseless
movement, alert and ready to become a useful cog in the next movement of
this myriad-minded machine. I jumped down into the pit. The great
gold-spotted toad stretched and scratched himself, looked at me, and
trembled his throat. I was not an army ant! The millipede cautiously
reared its head from the sand and felt timidly about.
I looked out and saw the last of the mighty army disappearing into the
undergrowth. I listened and heard no chirp of cricket, nor voice of any
insect in the glade. Silence brooded, significant of wholesale death.
Only at my feet two ants still moved, a small worker and a great
white-headed soldier. Both had been badly disabled in the struggles in
the pit, and now vainly sought to surmount even the first step of the
lofty cliff. They had been ruthlessly deserted. The rearing of new hosts
was too easy a matter for nature to have evolved anything like
stretchers or a Red Cross service among these social beings. The
impotence of these two, struggling in the dusk, only emphasized the
terrible vitality of their distant fellows. As the last twilight of day
dimmed, I saw the twain still bravely striving, and now the toad was
watching them intently. A poor-me-one called mournfully from a distance,
and I walked slowly toward home.
X
A YARD OF JUNGLE
Within five minutes the daily downpour of tropical rain would drench the
jungle. At this moment the air was tense with electricity, absolutely
motionless, and saturated with odorous moisture. The voices of all the
wild creatures were hushed. The sense of mystery which is always so
dominant in a tropical jungle seemed nearer, more vital, but more than
ever a mystery. Its insistency made one oblivious of the great heat. The
beating of one's heart became a perceptible sound, absurdly loud. All
the swamp and jungle seemed listening to it.
Suddenly a voice came out of the heart of this mystery, and fittingly
enough, the voice seemed something a little more or less than human, and
also fittingly it uttered but a single word, and that word a question.
And the listener realized that the answer to the question was the only
thing which made life and work worth while. The throb of the blood in
his veins was forgotten, and all his senses reached out to the sights
and sounds and scents about him. And again the great black frog called
from its slimy seat hidden in the still blacker water of the jungle
swamp. Its voice was deep, guttural, and a little inhuman, but it asked
as plainly as any honest man could ask, _Wh--y?_ And after a minute,
_Wh--y?_
I squatted in the center of a trail. Within walking distance behind me
flowed the yellow waters of the Amazon, and the igarape from which the
frog had called was even now feeling the tidal heave of the ocean.
Ahead, the jungle stretched without a break for three thousand miles or
more. And here for a week I had suffered bodily torture, twisting into
unhappy positions for hours at a time, watching the birds which crowded
the berry-laden foliage of a single jungle tree. In the cool of early
morning, throughout the terrible breathless heat of mid-day and the
drenching downpour of afternoon, the frog and I put our questions. There
was hope in our interrogation. And my five senses all gave aid, and my
hand wrote down facts, and my mind pondered them.
In the very suburbs of Para, at the mouth of the great Amazon and within
a hundred miles of the equator, I found a Mecca of bird-life. It was a
gastronomic Mecca to be sure, a tall, slender, wild cinnamon
tree,--_canella do matto_ the natives called it. For a full week I
invited torture by attempting to study the bird-life of this single
tree. This thing had not been done before; it might not be worth the
doing. But testing such possibilities are as important to a naturalist's
work as following along the more conventional and consequently more
certain lines of investigation. I had no time for exploration of the
surrounding country; so I had determined to risk all my precious hours
upon intensive observation in one spot.
The century before, a plantling had pushed up through the jungle mold
and had won success in the terrible competition of the tropics--the
helpless, motionless, silent strife of the vegetable folk. Year by year
the lichen-sculptured trunk had pushed its way upward toward light and
air, miraculously saved from the deadly embraces of the lianas which
crawled forever through the jungle. Today it had gained an accepted
place. Although no forest giant, with no great buttresses or masses of
parasitic growths, it held up its branches and twigs in full sunlight a
hundred feet or more above the ground. And its twiggy fingers were laden
with a wonderful harvest of fruit, uncounted berries which attracted the
birds from distant roosts and drinking places.
Here, then, a thousand combinations of fate had led me, and here I
suffered day by day. Bound to the earth like other normal men, my eyes
should have been directed forward. Now I forced them upward for hours at
a time, and all the muscles of neck and shoulders revolted. Then
eyestrain and headache and a touch of fever followed, and I cast about
for means to ameliorate my bodily ills. I dragged a canvas steamer chair
to my place of vigil and all my body was grateful.
In memory, there now remain only the highlights of new discoveries, the
colorful moments of unalloyed realization of success. Nevertheless this
new method of tropical work brought its own new delights and trials. One
joy lay in the very difficulties to be overcome. Every sense came into
play. Sight, first and foremost, had been put to the most severe of
tests in attempting to record the happenings against the glare of the
sky high up among the foliage of this bit of jungle. I strained through
my high-power glasses, until, when I looked without them, the world
seemed withdrawn, dwarfed, as in the horrid imaginings of fever. The
glasses gained in weight as I held them pointing vertically until they
fairly dropped from my aching arms. My ears strove to catch every song,
every note which might prove a character of worth. The jungle scents
played upon my emotions and sometimes dominated my work; the faint aroma
from some invisible orchid overhead, the telltale musk from a passing
mammal, the healthful scent of clean jungle mold. As for taste, I had
tested the aromatic berries and fruit of my canella tree, and for
science' sake had proved two warningly colored insects. My sense of
feeling had operated involuntarily and wholly aside from my scientific
desires. Whether stimulated by dozens of mosquitoes, scores of ants, or
hundreds of _betes rouges_ or "mucuims," the insistency of discomfort
never discouraged a primary desire to delve as deeply as possible into
the secrets of this small area of tropical jungle.
As I walked slowly about beneath the tree or lay back resting in the
chair, I seemed to be watching creatures of another world. Whether I
ogled them with glasses or now and then brought one down with a charge
of small shot, I was a thing of no account to the berry-eating flocks
high overhead. A vulture soaring lower than usual passed over the tree,
and the shadow of his partial eclipse of the sun froze every bird to
instant silence and complete immobility. But my terrestrial activities
wrought no excitement. The shot whistled through the foliage, one of
their number dropped from sight, and life for the rest went on without a
tremor. To ancestral generations, danger had come always from above, not
below.
The very difficulty of observation rendered this mode of research full
of excitement, and at the same time made my method of work very simple.
Against the sky, green, blue, or black feathers all appear black, and
the first two days my glasses helped but little. For several minutes I
would watch some tiny bird which might have been a yellow warbler had I
been three thousand miles farther north. After memorizing personal
characters, scrutinizing its flight and method of feeding, striving to
fix its individuality, I would secure the bird, and find in all
probability that it was a calliste, or tanager of brilliant plumage.
Tomorrow, if I were lucky, I might be able to tell off the numbers of
this species, to watch them and to know that I was watching them. But
recognition would not be by way of the cerulean or topaz or amethystine
hues of plumage, but by the slight idiosyncrasies of flirting tail or
wing or of general carriage.
Day by day, as I came to know better the jungle about me, I began to
perceive a phase which did not change. Even when the sun shone most
brightly, when the coolness of early morning had not yet passed, the
mood of the Amazon jungle remained. It was consistent, this low swampy
jungle, in its uniform, somber mystery. In spite of wholesale
exaggeration it was the dangers which came to mind. Of all places in the
world this was probably fullest of life, both in numbers and diversity.
Yet it was death--or the danger of death--which seemed in waiting,
always just concealed from view.
Beneath my tree I squatted silently. Just overhead the foliage might
have been almost northern. The finely cut leaves were like willow, and
at one side an oak, unusual but still an oak, reached out a thousand
thousand motionless leaves, breaking the glare into innumerable patches.
But ahead, the terrible interlacing of vines and thorny ropes, the
strangle-hold of serpentine lianas on every available trunk--all this
could be only tropic.
The ground glistened here and there with a film of black water which
revealed the swamp. Everywhere the mold and leaves of a hundred years
lay scattered, the last fallen still green. Many feet above, great fans
dangled, rayed fronds dry and crackling, fallen from high overhead, and
suspended, waiting for the interfering twigs and foliage to die in turn
and permit them to seek dissolution in the mold.
The jungle was bright with flowers, but it was a sinister brightness--a
poisonous, threatening flash of pigment, set off by the blackness of the
shadows. Heliconia spikes gleamed like fixed scarlet lightning,
zigzagging through the pungent air. Now and then a bunch of pleasing,
warm-hued berries reminded one of innocuous currants, but a second
glance showed them ripening into swollen, liver-hued globes which
offered no temptation to taste. One tree dangled hideous purple cups
filled with vermilion fruits, and not far away the color sequence was
reversed. A low-growing, pleasant-leaved plant lifted bursting masses of
purple-black, all dripping like wounds upon the foliage below. Many
flowers were unrecognizable save by their fragrance and naked stamens,
advertised neither by color nor form of blossom. I despaired of flowers
worthy of the name, until close by my foot I saw a tiny plant with a
comely, sweet-scented blossom, grateful to the eye and beautiful as our
northern blooms are beautiful. The leaf was like scores lying about, and
I realized that this was a sproutling of the giant tree. Nothing but the
death of this monster could give the light and air which the little
plant needed. It was doomed, but it had performed its destiny. It had
hinted that much of the beauty of the jungle lay far above the mold and
stagnant water. And then I remembered the orchids high overhead. And the
realization came that the low-growing blooms needed their glaring colors
to outshine the dim, shadowy under-jungle, and their nauseous fumes to
outscent the musky vapors of decay.
The plants of the jungle won success either by elbowing their neighbors
and fighting their path up to sunlight, or else by adapting their needs
to the starvation meed of air and light allotted to the lowly growths.
The big-leaved churacas had found another means of existence. They lived
like permanent rockets, bursting in mid-air. A long, curved stem shot up
and reached far out into space. It was so slender as to be almost
invisible in the dim light. At its tip radiated a great burst of
foliage, leaves springing out in all directions, and absorbing nutrition
which a sapling growing amid the undergrowth could not possibly do.
From daybreak to dark the canella tree was seldom deserted. Usually a
score or more birds fluttered and fed among its branches, and true to
tropic laws, there were comparatively few individuals but a multitude of
species. In the few hours I was able to devote to its study, I
identified seventy-six different kinds, and together with those which I
saw but could not name, I judge that more than a hundred species must
have come to the berries during that week in early May. The first day I
secured sixteen specimens, all different; and the following day yielded
fourteen more, only one of which was a duplicate of the first day's
results.
The bird visitors to the tree arrived in one of two characteristic ways.
Many came direct and swiftly, singly or in pairs, flying straight and
with decision. These came from a distance, with full knowledge of the
berries. They fed quietly, and when satiated flew off. The second method
of arrival was wholly casual,--loose flocks drifting slowly from the
neighboring jungle, sifting into the tree, and feeding for a time before
passing on. When these left it was rather hastily, and in answer to the
chirps and calls of the members of their flock who had not been beguiled
by the berries and hence had forged steadily ahead.
These more or less well-defined flocks are very characteristic of all
tropical jungles. Little assemblages of flycatchers, callistes,
tanagers, antbirds, manakins, woodhewers, and woodpeckers are drawn
together by some intangible but very social instinct. Day after day they
unite in these fragile fraternities which drift along, gleaning from
leaves, flowers, branches, trunks, or ground, each bird according to its
structure and way of life. They are so held together by an intangible
gregarious instinct that day after day the same heterogeneous flock may
be observed, identifiable by peculiarities of one or several of its
members. The only recognizable bond is vocal--a constant low calling;
half unconscious, absent-minded little signals which keep the members in
touch with one another, spurring on the laggards, retarding the
overswift.
While I watched, there came to my tree a single species of pigeon, two
hawks, and two parrots, four hummingbirds, and an equal number of
toucans and woodpeckers. The remaining fifty-nine were all passerine
birds, of which there were eight each of the families of flycatchers,
manakins, and cotingas. Eleven were tanagers.
The greedy, noisy parrakeets were always the center of commotion,
wasting more berries than they ate. The toucans, those bizarre birds of
whose lives we know so little, yelped and called and bathed in the water
caught in the stubs of branches, and fed to repletion. All the
flycatchers forgot their usual diet and took to berrying as ardently as
the tanagers themselves. Not all the birds came to feed on the berries.
A wren hunted insects among the branches, and a hawk found a giant
snail crawling up the trunk and devoured it. The insect-eaters of the
trunk numbered nine and showed no interest in the berries. Two were
woodpeckers and seven woodhewers.
These latter are a strange tropical family four hundred strong, and all
the very essence of protective coloring. Their habits of life make of
them wandering bits of bark, easy to detect when they are in motion, but
vanishing utterly when they are quiet. Their similarity in dress is
remarkable. They may be large or small, short or long-tailed, with beaks
blunt, sharp, straight, curved, thick, or needle-pointed. In these
characters they differ; by these points they must know one another. But
their colors are almost identical. Their olives or browns invariably
warm into rich foxy rufous on wings and tail, while over head and
shoulders a shower of light streaks has fallen, bits of sunlight fixed
in down.