model of high morality for the whole animal kingdom. Walled into the
tree-holes, the females obviously are helpless to protect themselves
against any infidelity, and, sad to say, there are vampire female
hornbills in the jungle whose only thought is to steal some imprisoned
lady’s spouse.
In the case observed by Dr. Kilham, however, the male preserved his
virtue to the end. “By November 8,” he records, “the female was walled
in, and a more serious attempt at interference was now made by a
foreign female.... She was following the male and lighted in the next
tree when he lighted above his nest hole. On November 23 the same
course of events took place, except that the male was less tolerant.
He fed his own mate, then drove the intruder away. A week later I saw
her fly in close behind the male and light 25 feet from the nest hole.
The male gave his mate a piece of bark followed by some fruit, and then
bounced from one branch to another toward the foreign female.”
The poor fellow was falling, falling, but “the female within the nest
screamed a number of times. I wondered whether the interloper could
seduce the male, but from subsequent observations it seemed unlikely
that she would. The male returned again to the nest hole, and a few
minutes later was in the upper part of the tree knocking about on dead
branches until he dislodged a piece of bark. He clamped his bill on
the bark until it was largely fragmented. Then he moved toward the
foreign female. If he presented the bark [a cherished play object among
hornbills] one would suppose that she had some attraction for him.
After a moment, however, he changed his direction, flew down to the big
limb below, bent over the nest hole, and gave the token to his mate,
accompanied by a feeding chuckle. Subsequently he returned to perch
quietly within eight feet of the intruding female. At 7:30 a.m. the two
of them flew away together. As the nesting season progressed, he became
less tolerant of her intrusions...On February 3 I again watched her
fly in behind the male and alight on the nest tree, making considerable
noise. The male stopped feeding his mate, swooped at the interloper
and drove her down toward the ground. However, when he flew away, she
followed a short distance behind.”
The vampire was hard to discourage. A few days later she was observed
at the entrance to the nest, trying to break the wall with her beak.
Probably there was a sex murder case in the making. But “After five
minutes the male arrived and...drove the foreign female to another
tree, flying at her so hard that he knocked leaves from intervening
branches. He returned to his nest with a small stick held like a cigar.
His mate, who had remained silent, now began her wailing screeches....
The intruding female, persistent as usual...had followed the male
back to the nest tree. In a few minutes he flew at her again, flying
faster than hornbills usually do as he chased her from one tree to
another.”
But his ordeal of bachelorhood was nearly over. Five days later mother
and young emerged from the nest: “The pair of hornbills were perched
side by side on their tree. Not long after I heard a great flutter of
wings. I looked back to see both members of the pair pursuing a foreign
female.... When the parents later came to our garden, she did not
follow.”
_Ants With Tailor Skills_
Ants developed the craft of sewing long before humans. There are
species of tailor ants in Australia, Africa and India that have
distinctly ingenious habits. They make nests of leaves sewed together
with silken threads, secreted by their own larvae, which they use both
as needles and shuttles.
When the nest is torn in any way certain soldiers and workers,
apparently specialized for this particular job, rush to the scene. The
soldiers arrange themselves to protect the workers. These first try to
pull the two edges of the rent together. If the gap is too wide for a
single insect to reach the other side and secure it with her mandibles
a living chain is formed, sometimes as much as six ants long. One holds
another in front of her with her mandibles, the second similarly holds
a third, and so on until the other side is reached. Hours sometimes are
required before the edges of the tear can be brought together and held
in contact.
Then several other workers appear, each carrying a larva head upwards.
These little worms are carried back and forth like a shuttle, spinning
the threads which are pushed through needle holes made by the workers
until the rent is securely patched.
_Fiend Symphonies of the Jungle_
Out of green jungle depths at sunrise rises the choral hymn of the
damned. It is a symphony of earth’s evil, of ancient dinosaurs and
flying reptiles, of vampires and witches. It comes from the throats of
jet-black, long-bearded, fiend-like creatures wearing red shawls. They
are the howler monkeys.
The world’s loudest-mouthed bluffers and braggarts are these dwellers
in the high treetops. They swear in an ancient tongue evolved over
centuries for the effective cursing of hovering white hawks, black
vultures and lurking wild cats. Now they curse, loudly and most
profanely, airplanes which sweep low over Panama and Costa Rican
jungles. They have not found it necessary to invent any new expressions
to convey their contempt for the new monsters of the skies.
Their voices are their only weapons. These have proved quite effective
throughout the lifetime of the race. The howlers have been able to
threaten their enemies with perdition so convincingly that these
enemies have believed the threats. Largely as a result, the big black
monkeys have been left alone as the dominant animals of the weird,
perilous green world at the top of the jungle. They never have had to
fight with fists, claws or teeth. All they have done—all it has been
necessary to do—is talk about it.
The scream of the howler, hurled defiantly at a possible enemy or
raised in a diapason to the sunrise or in a ritual of worship to the
full moon, is the most fearsome sound of the jungle. As one zoologist
has said: “It’s a combination of the bark of a dog and the bray of
a mule magnified a thousand-fold.” It can be heard, and clearly
discriminated, eight or ten miles away. Some say that the howl not only
sounds like the voices of fiends let loose from the pits of Hades, but
that the appearance of the animals themselves is just about what one
would picture for the infernal beings. The loudness and carrying power
is due to the monkey’s peculiar throat structure, which enables the
sound to reverberate. This throat structure is the weapon which nature
has provided for the animal and it has enabled him to more than hold
his own in the endless struggle for survival of the fittest. Even more,
it has made him supremely contemptuous of all lesser-voiced creatures,
such as men on foot or men in airplanes at whom he howls defiantly.
Of all apes or monkeys, the howler probably looks the least like his
distant cousin, man. He is at very best a grotesque caricature of a
chimpanzee or a gorilla. Attempts have been made to oust him from the
monkey race altogether and to degrade him to the pseudo-monkeys, the
lemurs. But in biology there is nothing to justify this.
Fortunately for students of animal behavior the howler is a daylight
animal. He usually goes to bed at sundown and stays there until
sunrise, except on occasions when the full moon awakens him and arouses
some uncontrollable frenzy which finds expression in the weird howling.
So about everything he does is open to observation.
The creatures remain about the least acceptable of the monkey and ape
race in human company. The feeling apparently is reciprocal. The howler
is an almost untamable wild animal. He never will dance at the end of a
hurdy-gurdy grinder’s leash, and seldom will be on exhibit in zoos. He
dies quickly in captivity, but only after becoming such a nuisance with
the howling of a broken heart that zoo keepers are glad to be rid of
him. Only one specimen has been kept in captivity at Barro, Colorado—a
baby rescued by one of the Indian guides after she had fallen out of
a tree. This happens not infrequently to the little howlers before
they have mastered the acrobatics of the forest canopy. They are not
climbers at birth, any more than seals are able to swim.
In the strange treetop realm among his own the howler is a much more
engaging personality than he appears down below. He is the “man” of the
green canopy 100 feet above the earth. He is the dominant creature,
intellectually if not always physically, and he appears to have evolved
a complex form of social organization.
From two to three hundred of the big black monkeys inhabit Barro,
Colorado. They are split into groups of from ten to twenty individuals.
These groups are probably extended families, each consisting of two or
three adult males, a few younger males, and the remainder females and
babies. Each clan possesses an area of from 250 to 500 acres. This is
the “home town” and few of the monkeys ever stray across its borders.
Within such an area are “roads,” path of long branches and heavy vines
by which a troop can pass easily from one treetop to another. These
same ways are maintained year after year. The howler requires solid
footing. Despite his lofty, wind-tossed habitat he is not much of a
gymnast. For one reason, his body is too heavy. He appears quite clumsy
compared with his lighter, more volatile relatives, the spider monkeys
of the same high realm. Howlers, for example, very seldom have been
observed leaping from tree to tree. Occasionally, probably only in
cases of dire necessity, a swinging vine may be used as a trapeze. Any
aerial acrobatics, however, appear far from this monkey’s ideas of good
sport.
Through its allotted area a group usually moves in single file, the
adult males leading the way and the females with young clinging to
their backs or breasts bringing up the rear. The treetop roads seldom
are wide enough to permit two monkeys to move abreast. When any of the
troop drops behind, the procession is held up to wait for him. If he
does not appear in a few minutes scouts are sent back to find out what
has happened. About the worst to be anticipated is that a mother has
dropped her baby. She immediately will descend to retrieve it from the
ground or, as is more likely, from some of the lower branches which
have broken its fall.
The animals appear to maintain a communistic family life. A family
never seems to increase or decrease in numbers. Probably new groups
are formed if the birth rate becomes greater than is necessary for
replacements. In the absence of epidemics death rates are not heavy,
for the animal has no very formidable natural enemies. Its hellish howl
is enough to scare away even the strongest, fiercest invaders of its
high country.
Classes are mutually exclusive. But there are no wars in the treetops.
When one group ventures near the border of a range claimed by another
all the inhabitants get together and set up the most fiendish howling
of which they are capable. The potential invaders stop and howl back,
just as fiendishly. After a more or less prolonged session of this
bloodless warfare both factions call it a day and go their peaceful
ways. Any actual fight between howler gangs has not been reported by
reliable witnesses.
_Tyrants of the Polychaete Race_
Knight-warriors and Amazons of the worm world are the aphroditids. They
are the aristocrats and tyrants of the polychaete race.
Like the oriental Aphrodite whose name they bear—she was the mythical
goddess of love and war who rose from the sea foam armed with golden
spears which were the rays of the moon and sun she personified—they
crawl over the beach sands resplendent in a bristling panoply of gold
and green. Heavily armed for both offense and defense, their prey are
all living things remotely their equals in size and strength.
For their battles they carry on their feet “an armory of harpoons,
bayonets, lances, spears and billing hooks,” says the Rev. George
Johnston in his catalogue of annelid worms in the British Museum.
“Were it desirable to have any additions to man’s weapons of war,” he
comments, “the aphrodite bayonet might furnish a model for a new kind
as formidable as any we possess. It is armed with a kind of pricker
affixed to the end of a musket. This appendage is very sharp, formed
with several cutting surfaces, and with a spine below pointed backwards
which gives it the properties and advantage of a harpoon. Hence, having
been forced to penetrate the flesh, the point cannot be withdrawn, but
is detached at once.
“This, however, is not the most curious part of the instrument. The
bayonet part of the bristle is, in fact, a sheath which encloses
another weapon that is exposed only when the scabbard is lost. When we
detach the bayonet from the sheath, at the same time we force from its
interior a horny stylette with a needle-like point ready to become a
good defensive weapon.”
The terror of tidal beaches described by Dr. Johnston is the “sea
mouse,” Aphrodite aculeata, an oval-shaped worm from six to eight
inches long and two or three wide. It has from 30 to 50 large “feet”
on each side of its body, each carrying an immense tuft of silky green
and golden bristles and spines. Many have commented on the malevolent
creature’s beauty and capacity for inspiring terror.
“The very brilliant iridescent hues,” Dr. Johnston says, “are not
equalled by the colors of the most brilliant butterflies.” “It does not
yield in brilliance to the plumage of humming birds or even to the most
shining gems,” wrote the great French naturalist Baron Cuvier, credited
with the original description of the animal.
Normally it moves by jet propulsion. As it goes forward, a current of
water is projected with considerable force at short intervals from its
rear end. Progress ordinarily is slow, but the sea mouse is capable of
considerable speed when pursuing a slow-moving prey. It frequently can
be observed motionless, watching a weaker worm or mollusk upon which it
is prepared quickly to pounce at a favorable opportunity.
Some of these animals, Dr. Johnston observes, “have 500 feet on each
side of the body. Each foot has two branches and each branch at least
one spine and one brush of bristles. Thus an individual has at least
1,000 spines. If we reckon ten bristles to each brush, it has at least
10,000.”
The bristles, presumably, are almost entirely for defense; the spines
for offense, and admirably fashioned for killing weaker animals. Both
types of weapons can be retracted entirely inside the foot when not in
use, but thrust out again immediately when needed.
Aphrodite hermione, a close relative of the sea mouse, Dr. Johnston
points out, “has in the dorsal branch of its feet bristles which may
be described as lances. They are so small that a magnifying glass is
needed to discover the workmanship, which excels in finish the finest
instrument of man by the skill of the most expert artificer. A great
number of these bristles garnish the extremity of each foot, and as
they are stiff and serially arranged they form a hedge of spears around
the body of the worm, placing it within a square of pointed pikes
threatening at all points. Other bristles terminate in a knob within
which is a barbed lance.”
Still others are likened by Dr. Johnston to harpoons, produced from
the body only as required. They are very sharply pointed bristles with
the point attached to a shaft. The harpoon point, like the bayonet
previously described, has a reverted tooth which cannot be withdrawn
once it has been plunged into the body of the enemy. It can, however,
be detached and left to fester in the wound. Some worms lose all their
harpoons in their many fights.
“There is scarcely a single weapon invented by the murderous genius
of man,” commented the French naturalist Quatrefages concerning
aphroditids on Bay of Biscay coasts, “whose counterpart and model
could not be found among these worms. Here are the curved blades whose
points present a double and prolonged cutting surface, sometimes on the
concave edge as in the yataghan of the Arabs, sometimes on the convex
border as in the oriental scimitar. We meet with weapons of offense
and defense which remind us of the broad sword of our cuirassiers;
the sabre-poignard of the artilleryman; the sabre-baionette of the
chausseurs. We have harpoons, fishhooks, cutting blades in every form
attached to the extremities of sharp handles. Destined to live by
rapine and exposed to a hundred enemies, they need such weapons both
for attacking and defense.”
Some aphroditids swim with ease. The majority, however, are found
between tide marks where they burrow in wet sand. A few occasionally
trespass in tidal rivers. When placed in fresh water the animals soon
die, in their death throes first ejecting a milky-white fluid which
turns to blackish-green at the moment of death. Despite their heavy
armament, the aphroditids are a favorite food of codfish. They are
distributed generally all over the world. The monster of the race in
the South Pacific sometimes reaches a length of five feet.
_Eating Habits of Spiders_
Spiders digest most of their food before eating. They must subsist on a
liquid diet. A powerful digestive fluid from the stomach is discharged
on the prey. This completely liquifies the soft tissues. So potent is
this fluid that spiders sometimes can devour small back-boned animals,
such as fish and lizards, which they kill with their poison fangs. One
African species can liquify almost completely a fish two inches long
in less than three hours. Another has been observed in captivity to
dispose of small snakes in the same way.
_The Suicide Instinct of Iguanas_
Some iguanas seem to have the ability to commit suicide without any
visible means. Some of these lizards, hitherto unknown to science,
captured alive and uninjured in Cuba by Dr. Paul Bartsch of the
Smithsonian Institution, died a few minutes later as if a mere wish to
end their lives were sufficient to achieve death.
“These iguanas are vegetable feeders,” Dr. Bartsch recorded in his
field notes. “They are fairly tame and persisted in chasing the nooses
on the ends of our sticks, instead of running their heads through them
or letting us place them around their necks. When hard-pressed they
finally dash into holes that look like huge crab burrows. When near the
coast, where there is a hurricane rampart, they seek refuge in crevices
of the rocks. We were surprised when we took those we had captured from
our bag on board ship to find four of them dead. Evidently they have a
way of ending their own lives.”
On Petite Gonave Island off the coast of Haiti are large iguanas
which—native fishermen say—can be captured safely only by getting them
drunk. Travellers are warned that they are extremely dangerous animals
when sober. The fishermen pour rum into hollows of rocks along the
shore. The big lizards appear to be very fond of this beverage and
drink themselves helpless.
_Forests That Eat Meat_
Relic groves of the great meat-eating forests of 150,000,000 years ago
still thrive on the floors of deep, warm seas.
These are made up of plant-animals—predacious trees with red blood
and hearts—the crinoids. There are about 700 extant, compared to more
than a thousand extinct, species. For a hundred million years they
were among the ocean’s dominant life forms. Fossil crinoids, or “stone
lilies,” make up great marble beds in both American and Europe. In 1934
the Smithsonian Johnson expedition dredged nineteen species, including
two not hitherto known to science, from the bottom of the great Porto
Rico Deep.
The crinoids are highly developed animals, although they look like
plants. They can by no means be considered as a form of life on the
dividing line of the animal and vegetable worlds. Rather they are
animals which have taken on the superficial appearance of plants. They
are very highly specialized animals—so much so that there are few
places in the world where they can survive in great numbers.
In life they usually are brilliantly colored. Judging from those that
are found on the sea bottoms today one of the ancient meat-eating
forests must have presented a very colorful spectacle of red, green,
purple and yellow “blossoms.”
Most of them live in deep water. There are free-moving varieties as
well as those that are fixed to the bottom with stems like plants.
Until recent years few were recovered in good condition because of the
tendency of one of these plant-animals to break itself to pieces when
agitated. When brought up from the bottom to the deck of a ship the
crinoid would proceed to break off the featherlike arms which make up
the blossoms. This was its natural defense reaction in the depths. Its
way of escape when one of its arms was seized by a fish was to break
it off. Then it could grow another quite easily. As a matter of fact,
this is the way the crinoid grows—one of the most wasteful processes of
growth in nature. It breaks off one arm and grows two instead; but it
cannot increase the number of its arms without discarding an old one.
Another difficulty is that the gorgeous colors of the meat-eating
flowers are fast only in salt water. They fade rapidly in air, fresh
water or alcohol so that there can be only a fleeting impression of the
true coloration.
These crinoids live, for the most part, on diatoms, small crustaceans,
and other tiny sea creatures which they first paralyze with poison from
the tentacles which line the grooves of the arms through which food is
carried to the mouth.
_Cave-Dwelling Birds_
True creature of night is the guacharo, or “oil bird”, of northern
South America. It is reddish-brown, about the size of a barnyard hen.
Excessive layers of fat built up about its abdomen formerly were valued
highly by natives for eating purposes, resulting in the slaughter of
countless thousands every year. The guacharo spends its days a half
mile or more deep in the interior of mountain caves. Here it roosts
and builds its nests in crevices high in the rock walls. It leaves in
groups of twenty to thirty shortly after dusk and apparently spends the
whole night foraging for food, sometimes covering as much as 200 miles.
Like the cave bat, it seems to have no difficulty finding its way
in absolute darkness. An explanation of this ability, acoustic
orientation, has been reported by Dr. Donald R. Griffin of Cornell
University. The birds apparently are guided by echos of specific sharp
“clicking” sounds which they make.
“The individual click,” Dr. Griffin explains, “consists of a very few
sound waves having a frequency of about 7,000 cycles per second. The
duration of each click is about a millisecond (1,000th of a second).
The clicks were loud enough to be audible easily about 200 yards
inside the cave. Except for their lower frequency, these sounds are
very similar to those used by insectivorous bats for their acoustic
orientation.
“The external ear canals of three captive birds were plugged with
cotton. They then became disoriented when flying in the dark. They
collided with every object they encountered. Before and immediately
after this treatment they flew about in a small dark room avoiding all
collisions with the walls.”
Their best known habitat is the guacharo cave in Venezuela’s Humboldt
National Park, where they are rigidly protected. Most of them nest
in a vast subterranean hall more than a half mile long and a hundred
feet high. Here more than a thousand of the birds greet the intruder
instantly with a wave of awesome and deafening shrieks.
“With the advent of dusk,” reports Dr. Eugenio de Bellard
Pietri—Venezuelan cave explorer, “the birds come out in compact groups
but before the exodus a preliminary flight is held by a few as if
to make sure that night is falling. Soon they return to the depths
of their somber mansion, evidently to give the flock the all clear
signal. Late in the evening there is not a single adult specimen left
in the cave. The flight of these birds is silent and cannot easily be
detected.”
_Where Snails Become Flowers_