If
asked to name the bird they would least like to meet, many would say the
vulture.
Few birds have been so vilified as the
vulture. It is the accursed bird whose sinister silhouette wheels over the dead
and the dying. Its appearance is said to herald carnage, desolation, and
despair. But such is the stuff of fiction.
As for the facts: Many have been enthralled
by the vulture’s grace in flight and the tender way it cares for its young.
They have also discerned its important ecological role. To such ones the
vulture is both magnificent and indispensable.
Admittedly, vultures have a few things
against them, apart from their unsavory feeding habits. They would certainly
not win any beauty contests, and their calls have been variously described as
squeals, cackles, grunts, croaks, and hisses. They do, however, have some
endearing qualities.
The vulture is a bird that takes parenthood
very seriously. Every year an “only child” receives the undivided attention of
both parents until it can fend for itself. A young vulture chick perched
helplessly for several months on an inaccessible ledge certainly needs the
compassionate care of both parents. In fact, a young Andean condor has to be
fed for six months before it can leave the nest, by which time the “chick” is
nearly full-grown.
And vultures have the virtue of being
eminently useful. Although many birds benefit mankind in one way or another,
vultures perform a unique service. They are sanitary inspectors of the skies.
Sanitary Inspection
Cleaning up carcasses is not everybody’s idea
of a favorite daily chore, but it is an important job. Proper sanitation
requires the prompt removal of dead bodies, which can be dangerous sources of
infectious diseases for both man and beast.
Here the vultures come into their own. Even meat
contaminated with anthrax or botulin is gobbled up with impunity, until nothing
remains but the bones.
Some vultures even specialize in eating
bones. The lammergeier vulture of Eurasia and Africa drops bones from a height
onto a rocky surface. When the bones split open, the lammergeier eats the
marrow and the smaller pieces of bone.
Fortunately, unlike their human counterparts,
these sanitary inspectors have never gone on strike. If the vultures’ work was
left undone, tropical plains littered with disease-ridden carcasses would be a
familiar sight.
But let us follow a team of vultures on a
typical workday.
Skyway Patrol
Soon after sunrise, they take to the skies,
each one to cover a certain area. Throughout the day our squadron of vultures
tirelessly patrols the skies in search of dead animals. When a carcass is
finally spotted by one of their number, he goes into a steep dive. This
attracts the attention of the other birds, who also hasten to the spoil. Within
minutes, dozens of birds arrive at the scene.
Before eating, the birds hop around the
carcass hesitantly. Despite their reputation, they are extremely shy creatures.
Finally, one of them starts tearing at the carcass, and this is the signal for
the whole group to attack the meal. There is a lot of squabbling and hissing,
pushing and pulling, which looks uncannily like a rugby football scrum. The
hungriest, who protest the most energetically, usually get fed first. If it is
a large carcass, there will be enough food for all.
In a matter of minutes, the meal is over, and
leaving only the bones, the flock takes to the sky to continue the search. A
vulture’s life is not an easy one. It may be two or three days before they have
another meal.
Eyesight and Teamwork
Vultures are admirably equipped for aerial
surveillance. Their massive wings are perfectly designed for gliding and
soaring, enabling them to fly for hours with barely a wing beat. They are adept
at taking advantage of thermals, or rising hot-air currents, which serve to
keep them aloft with minimal effort. Dean Amadon, prominent American
ornithologist, described them as one of “nature’s most eloquent expressions of
flight.”
A question that intrigued ornithologists for
many years was, How do vultures find carcasses so quickly?
The answer turned out to be a combination of
sharp eyesight and teamwork. It has been calculated that a vulture circling
overhead at a height of about 2,500 feet [750 m] can
spot an object on the ground that is less than five inches [13 cm]
long. But even with such penetrating vision, a lone vulture would be
hard-pressed to find food.
Hence, teamwork is essential. It has been
observed that vultures divide up to patrol different areas. If one vulture
descends toward a carcass, his distinctive swoop is the signal to nearby birds
that food is in the offing, and they immediately fly in that direction. Their
change of course is likewise spotted by more distant birds, who also hasten to
the scene. This aerial telegraph system is surprisingly efficient, so much so
that it may appear to an observer that all the birds arrive almost
simultaneously.
Sadly, such efficiency and undeniable
usefulness have not sufficed to guarantee the vultures’ protection and
survival.
The Return of
the Condor
Despite being counted among the largest and
most impressive birds of prey, vultures are facing extinction in many parts of
the world. Their traditional food has disappeared from the plains, and not
infrequently the carcasses they do find have been poisoned. Their slow breeding
rate also makes it difficult for their decimated populations to recover.
Nevertheless, there are some heartening
success stories. A program for the artificial breeding of California condors
seems to be proving successful, and it is hoped that more birds can soon be
returned to the wild. Thanks to the efforts of French conservationists, the
griffon vulture has reestablished itself in the Massif Central, France, after
an absence of many years.
Thus, the bird that people once loved to hate
has become a symbol of man’s efforts to save those species that he has
endangered. Undoubtedly, the majestic flight of the condor over the sierras of
North and South America is a sight too precious to squander.
Meanwhile, in Africa and Asia, the vultures
still unassumingly perform their thankless task, that of sanitary inspectors of
the skies.
Vultures on Record
VULTURES are counted among the rarest and largest birds of the world.
And they hold the avian altitude record as well.
The California condor is one of the most endangered species in the
world. To save this vulture from extinction, strenuous efforts are being made
through a breeding program among the two dozen birds in captivity. In 1986 only
three California condors were left in the wild.
The Andean condor, along with the marabou stork of Africa, has the
greatest wingspan of all land birds, over ten feet [3 m]. It
is also the heaviest bird of prey, sometimes weighing in at over 30 pounds
[14 kg].
Vultures are high fliers as well. In 1973 an African vulture (Gyps
rueppellii) collided with an aircraft that was flying over Côte d’Ivoire,
West Africa, at an altitude of 37,000 feet [11,300 m].
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