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Eagles generally kill their prey before carrying it off,
and the maximum load for the golden eagle is usually only
about 4-5 kg, observes Nutan
Shukla
They invoke fear
and admiration
FOLKLORE abounds with stories of
birds carrying fantastic weights, but most are entirely
fanciful. They generally involve birds of prey which have
always filled man with admiration, and even fear. Yet the
largest raptors, the vultures, are primarily carrion
feeders and have neither the reason nor the claws for
great lifting feats. Thus it is to the eagles that man
has turned his attention, and of these the very
widespread golden eagle has been the subject of most
stories.
Eagles generally kill
their prey before carrying it off and the maximum load
for the golden eagle is usually only about 4-5 kg. But
when birds have been disturbed at a kill or sense that a
rapid exit is advisable, then there is reason to tackle
greater loads.
Most tales of human babies, children and
even adults being carried off by eagles have, not
surprisingly, been disregarded by ornithologists, but
there is at least one case which is apparently fully
authenticated. In 1932 a four-year-old Norwegian girl is
said to have been carried off by a white-tailed sea eagle
while she was playing in the yard of her parents
farmhouse. The huge bird tried to carry the girl
(apparently small for her age) back to its eyrie 800 ft
up the side of a mountain more than 1.6 km away, but the
effort was too great and the poor child was dropped on a
narrow ledge about 50 ft from the nest. Fortunately, a
search party organised by the desperate parents
pinpointed the eagle soaring above the eyrie and the girl
was found in an unconscious state, but unharmed, except
for some scratches and bruises. One theory is that the
bird had the advantage of the powerful up-current of air.
But whatever the truth, the girl, Svanhild Hansen, grew
up happily and kept the little dress she wore that
terrible day, with the holes made by the eagles
talons.
The diet of the
white-tailed sea eagle in Norway is generally 60 per cent
fish and 40 per cent birds but may reach 90 per cent fish
in some areas. They sometimes kill Arctic foxes and
lambs, but mammals are mostly eaten only as carrion.
Where fish are too large to lift, the bird will tow them
to land by rowing with its wings. The largest
prey so far seen taken in flight is the greylag goose,
which rarely has a maximum weight of about 4.25 kg.
Another member of the
family is harpy eagle, which is probably the most
aggressive and powerful true eagle. It is a formidable
aerial hunter of the jungles of Amazon. Many experts are
of the opinion that this bird should be given pride of
place in the entire bird of prey family. Inhabiting the
lowland tropical forests, harpy is a very agile hunter,
despite its huge size. While on a hunting expedition it
cruises through the canopy of the jungle trees at a speed
of about 80 kph, chasing monkeys that make up a major
part of its diet. It also feeds on sloths, tree
porcupines and other tree-living creatures. It is expert
in killing and carrying off monkeys and sloths. Its
short, broad wings help it to lift prey almost vertically
and there is a report of a female rising over 18m with a
5.9 kg sloth in her massive claws.
Other reported great lifts
include a Pallass sea eagle barely managing to fly
with a carp of 5.9 kg in India, and an American bald
eagle flying well with a 6.8 kg mule deer in its talons.
It is generally assumed that larger individuals among
eagles can carry larger weights and it has been suggested
that a very large female Stellers sea eagle of 8.6
kg could probably carry a 9.1 kg young seal for several
hundred metres.
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